Acanthus spinosus
Acanthaceae
bear’s breech
One of the most architectural of perennials, bear’s breech’s bold leaves—variously lobed, cut, and divided, some tipped with spines—inspired the decorative foliage on Corinthian column capitals. The bracted, tubular flowers, borne in dramatic spikes above the foliage, are mostly white, often almost concealed by a purple or mauve hood, and are excellent for cut flowers, fresh or dried.
These are not plants for tight conditions or for the faint of heart. Bear’s breech can take over a small space and is considered by some to be invasive, especially on favorable sites—its tenacious roots are almost impossible to eradicate. Established plants tolerate drought well, though good drainage is critical. In cold-winter climates, apply a protective winter mulch.
A fine subject for large containers for a deck or patio, bear’s breech also stands out massed beside lightly shaded driveways or on the edge of woodlands, where it can spread freely. In flower borders, protect from intense sun. Garden phlox, upright milky campanula, and meadow rue are good back-of-the-border companions. Underplant with geranium ‘Rozanne’ or sweet woodruff. Seldom browsed by deer.
Propagate by division or by detaching young plants from the base in spring or fall. Sow seed in spring, or take root cuttings when the plants are dormant.
Acanthus hungaricus
syn. A. balcanicus, A. longifolius
• white, purple
• late spring to summer
• 3–4 ft. × 3 ft.
• sun, part shade
• Z6–10
Balkan bear’s breech. Southeastern Europe. Clumps of deeply divided, dull green leaves are thistle like but lack spines. White flowers are hooded with plum bracts equipped with spines.
Acanthus mollis
• white, purple
• late spring to summer
• 4 ft. × 3 ft.
• sun, part shade
• Z7–10, HS
Bear’s breech. Southeastern Europe, northwestern Africa. Deeply lobed, glossy leaves to 2 ft. long. Slow to establish, especially when grown from seed. Intolerant of heat coupled with humidity.
‘Hollard’s Gold’ emerges with bright gold foliage in spring, which unfortunately matures to green. Can be used as a startling focal point to contrast with ostrich fern (Matteuccia struthiopteris) in light shade, or as a specimen or container plant. Spikes of white and wine-colored flowers rise to 5 ft. tall all summer long.
‘Rue Ledan’ thrives in hot, humid conditions. Clumps of handsome, shiny leaves may reach 3 ft. across. Spikes of pure white flowers rise to 3 ft. Not as heat tolerant. Z6–8.
‘Whitewater’ bears eye-catching, deeply cut leaves generously splashed and tipped with white, and white-and-pink snapdragon-like flowers in summer. Tough, excellent in difficult areas.
Acanthus spinosus
syn. A. spinossissimus
• white, purple
• summer
• 3–4 ft. × 2–3 ft.
• sun, part shade
• Z6–9
Bear’s breech. Eastern Mediterranean. This species does not establish quickly but is worth the wait. The thistle-like, dark green leaves are glossy and variably spiny.
Other Notable Cultivars
‘Holland Days’, often listed under Acanthus spinosus, has deeply cut, sharply pointed (but not spiny) leaves, and purple-bracted, white flowers. Ideal for smaller gardens, but beware of its invasive tendencies. 1 ft. × 3 ft. Z6–10.
‘Summer Beauty’ sports huge, deeply cut, shiny, dark leaves; 4- to 6-foot flower stems with mauve-bracted, white flowers. Tolerates southern heat and humidity. Z6–10.
Asteraceae
yarrow
Summer-blooming yarrows are major players in sunny ornamental gardens. Their ease of culture and sturdy constitution reward beginners and experienced gardeners alike. A few low-growing species, such as Achillea ageratifolia and A. tomentosa ‘King Edward’, are best suited to rock gardens, but the majority of yarrows are upright and suitable for mixed and perennial borders, and butterfly, wildlife, and cutting gardens.
Foliage is green or silvery gray-green, finely divided, and has an aromatic odor that deters browsing by deer and rabbits. Fibrous flower stems are crowned with flattened simple or compound heads of colorful, little daisy flowers, the outer all female and the inner bisexual and mostly yellow. Excellent as fresh or dried cut flowers; harvest in the cool of the day, taking flowers on which pollen is visible for longest vase life.
Yarrows thrive in most well-drained soils and tolerate drought when established. Also tolerant of salty winds, and excellent in coastal gardens. For best results, grow in full sun with lean soil; poor drainage and rich soil encourages soft, disease-prone growth that may need staking. After blooms are spent, deadhead to the ground. To maintain vigor, divide plants every two to three years.
Complement yellow-flowered achilleas with blue delphiniums, red hot pokers, monkshood, and bellflowers, or create a monochromatic design with yellow coreopsis, goldenrods, and yellow-toned daylilies. Pink and red yarrows are handsome planted with daylilies of similar hues; the habits and flower shapes contrast well.
Propagate named cultivars and hybrids by division or soft cuttings in spring; sow seed of species in spring.
Achillea filipendulina
syn. A. eupatorium
• yellow
• early summer to early fall
• 3–4 ft. × 2–3 ft.
• sun
• Z3–9
Fern-leaf yarrow. Caucasus. Rosettes of aromatic, deeply cut, greenish foliage give rise to strong stems topped with 4- to 5-in.-wide, golden flowerheads. Requires lean, very well-drained soil.
‘Cloth of Gold’ has brilliant yellow flowerheads. Tolerates very light shade. Comes true from seed. 4–5 ft. tall.
‘Gold Plate’ is one of the tallest yarrows, with 6-in.-wide heads of bright golden flowers. Tolerates heat and humidity well. Z3–8.
‘Parker’s Variety’ is another fine selection with large, golden flowerheads. 4–5 ft. Z3–8.
Achillea grandifolia
• white
• summer to late summer
• 3–4 ft. × 2 ft.
• sun
• Z5–8
White yarrow. Turkey and the Balkans. An uncommon species worth seeking out. Large, fern-like, cut, gray-green leaves; strong stems bear 3-in.-wide heads of clean white flowers. Great companion for vibrant echinaceas, daylilies, and checker mallows.
Achillea millefolium
• white
• summer to early fall
• 2–2.5 ft. × 4 ft.
• sun
• Z3–9
Common yarrow, sneezeweed, soldier’s friend. Temperate regions. Weedy, a poor garden plant but parent of many fine selections and hybrids. Divide every two to three years to maintain vigor.
‘Apfelblute’ (‘Apple Blossom’) has soft lilac to rose flowerheads, and green foliage. Excellent for massing.
‘Apricot Delight’, sometimes called ‘Tutti Frutti’, has salmon, deep and light pink heads of flowers above grayish foliage. Compact, suitable for containers. 15 in. tall.
‘Oertels Rose’ sports strong, non-fading pink flowers. 12–24 in tall.
Achillea millefolium ‘Oertels Rose’
‘Paprika’ has dusty red flowers in 2- to 3-in. heads. Mid-green foliage. Pinch to control height, especially in hot, humid climates. Deadhead for rebloom. 18–36 in tall.
Seduction Series is a strain bred for their stellar performance in the hot, humid climates of the Southeast. Sturdy, upright, and compact. 18–24 in. Z4–8.
Achillea ptarmica
• white
• early summer to fall
• 18–24 in. × 24 in.
• sun, part shade
• Z3–9
Sneezeweed, sneezewort, bridewort. Europe. With 2- to 3-in.-long, lanceolate, green leaves and branched stems, sneezeweed is not the average yarrow. Loose clusters of button-like, single or double, white flowers top slender stems like a bouquet. The foliage has been chewed to quiet a toothache or dried for use as snuff. May spread in average soil; best where the soil is poor and dry. The double forms are most popular.
‘Ballerina’, a dwarf version of 2-ft.-tall ‘Angel’s Breath’, is a baby’s breath lookalike. Long blooming. Deadhead to prevent self-seeding. 12 in. tall.
‘Perry’s White’. Pure white, double flowers make this superior to rather dingy ‘The Pearl’. Upright and vigorous but may become floppy; provide support. 30 in. tall.
‘Stephanie Cohen’ may be listed under Achillea sibirica. Pale pink flowers are carried in clusters 2–4 in. across. Named for American horticulturist Stephanie Cohen. 15–24 in. tall.
Achillea tomentosa
• yellow
• summer
• 8–15 in. × 18 in.
• sun
• Z3–9, HS
Woolly yarrow, dwarf yarrow. Western Asia, southern Europe. Evergreen mat-former with aromatic, gray foliage finely divided and covered with soft hairs. Clusters of bright yellow flowers attract birds and butterflies throughout the summer. Site in poor, free-draining soil. Excellent in rock gardens, but it has invasive tendencies. Drought tolerant; ideal for xeriscapes.
‘Aurea’, golden creeping yarrow, bears lemon-yellow flowers on 6- to 10-in. stems. ‘Maynard’s Gold’ may be a synonym.
‘Goldie’ has bright golden flowers. 6–8 in tall.
‘King Edward’. An old cultivar, often listed as Achillea ×lewisii. Creamy-yellow flowers. 8 in tall.
Other Notable Cultivars
Anthea (‘Anblo’) is a heat-tolerant, clump-forming British hybrid with summer to early fall bloom. Pale yellow flowerheads, 3 in. wide; soft silvery foliage. Deadhead or cut plants by half after the first flush. 18–28 in. × 36 in. Z3–9.
‘Coronation Gold’ (Achillea clypeolata hort. × A. filipendulina). Perhaps the most popular yarrow for long-lasting cut flowers. Plate-like, 3- to 4-in. inflorescences in late spring to late summer. Aromatic, gray-green, ferny foliage. Tolerates heat, humidity, and dry spells with aplomb. Divide every three to four years. Partner with mauve and purple asters. 2–3 ft. × 2 ft. Z3–9.
Achillea ‘Coronation Gold’ contrasts vibrantly with blue salvias and geraniums
Galaxy Hybrids (A. millefolium × A. ‘Taygetea’), a fine strain with heads of pink, red, or yellow flowers from late spring to midsummer. Select superior colors; colors may fade in intense sun. Propagate by division. 2–3 ft. × 2 ft. Z3–9.
‘Moonshine’, an Alan Bloom hybrid, has wide, long-lasting, bright yellow flowerheads from early summer to fall; finely dissected, fragrant, silvery foliage. Cut back after first floral flush for rebloom. Sensitive to heat and humidity. Partner with daylilies, speedwells, and bellflowers. 18–24 in. × 18 in. Z4–8, HS.
Summer Pastels strain has green foliage and flowerheads in pinks, purples, yellows, and white. Less aggressive than many yarrows. Blooms first year from seed. 24–30 in. tall.
‘Terra Cotta’ has silvery foliage and heads of flowers that range in color from peach and salmon to burnt orange. 3 ft. tall.
Achillea ‘Terra Cotta’
‘Taygetea’. Rich gray, dissected leaves provide a fine foil for soft lemon flowerheads; summer to fall. Easy to grow, undemanding, perfect for smaller spaces. Not to be confused with weedy, white Greek yarrow, A. taygetea. 12–18 in. × 18 in. Z3–10.
Ranunculaceae
monkshood, aconite
This genus of 250 or more species has accumulated a wealth of common names, including wolf’s bane, leopard’s bane, helmet flower, and devil’s helmet, most of which refer to the plants’ poisonous qualities or the helmet-like shape of the flowers. All parts of the plants are toxic; the sap (containing the poison, aconitine) has found use as a poison to tip arrows for hunting and war. Even so, a number of species and hybrids are definitely garden worthy, though they should never be planted where children play or near vegetable or herb gardens. Aconitum nomenclature is very confused; locating a recommended species may involve searching under the synonyms included in the descriptions below.
Monkshoods usually have tuberous roots that give rise to upright stems clothed with attractive, alternate foliage, deeply cut, dissected, or lobed. The 1- to 2-in. flowers are hooded or helmet shaped with a large sepal that protects the sexual parts. Blooms are borne in long racemes or panicles, up to 20 in. long, raised well above the mass of foliage.
Although they prefer part shade, monkshoods accept full sun where summers are temperate as long as the soil does not dry out. Ideally, soils should be fertile, cool, and moisture retentive but not waterlogged. Maintenance is minimal; deadhead spent flower spikes to their bases only, as lateral branches will bloom later. Some species may require staking. Always wear protective gloves when working with aconitum and avoid exposing open wounds or eyes to the sap. Never decorate a plate of food with the blooms. In beds and borders, summer phlox, assorted daisies, and daylilies are good companions; avoid placing the blue-flowered monkshoods against a dark background as the flowers tend to disappear.
Resistant to deer and rabbit browsing. Bumblebees pollinate the flowers and suck nectar from the end of spurs under the hood.
Divide the tuberous roots in fall or early spring every three years or so to maintain vigor and to increase. Start from seed in spring.
Aconitum ×cammarum
syn. A. napellus var. bicolor, A. ×bicolor
• various
• summer to fall
• 3–4 ft. × 2 ft.
• sun, part shade
• Z3–7, HS
Bicolor monkshood. Of garden origin. Probably a cross between Aconitum napellus and A. variegatum. Habit varies from stiffly erect to more relaxed. Lustrous, deeply five- to seven-fingered, dark green, 2- to 3-in. leaves.
‘Bicolor’ (syn. A. ×bicolor) bears wide, loosely branched panicles of 1.5-in., white, helmet-shaped flowers edged with blue; midsummer. May need staking. 4 ft. tall.
‘Bressingham Spire’ has narrow wands of violet-blue flowers on sturdy stems that seldom need staking. 2–3 ft. tall.
Aconitum carmichaelii
syn. A. fischeri
• deep blue
• late summer to early fall
• 2–5 ft. × 2 ft.
• sun, part shade
• Z3–7, HS
Azure monkshood, autumn-flowering monkshood. Central and western China, North America. Tuberous roots give rise to erect stems to 5 ft. tall under ideal conditions; more often 2–3 ft. Handsome leathery, dark-green foliage is deeply cut into three to five lobes. Dense, 8-in.-long panicles of large, violet or deep blue flowers. Prefers consistently moist soils; a fine choice for wet soil beside water features, in damp woods, and rain gardens.
‘Arendsii’ (syn. Aconitum ×arendsii). Branched panicles of large, strong azure-blue helmet flowers in fall. Stout stems seldom need staking. Introduced by Georg Arends of Germany. 2–4 ft. tall.
Aconitum carmichaelii ‘Arendsii’
‘Barker’s Variety’ has loose spikes of deep violet flowers in fall. Start from seed. To 6 ft. tall.
‘Cloudy’, a mutation of ‘Arendsii’, is upright, with thick stems and lots of bicolored, light-blue-and-white flowers. 34 in.
Aconitum henryi
• indigo blue
• summer
• 4–5 ft. × 2 ft.
• sun, part shade
• Z3–7
Henry’s monkshood. Western China. Sturdy lower stems, but upper ones are thin and may even semi-twine. Foliage is not as leathery as Aconitum carmichaelii’s, but is divided into three to five lobes almost to the leaf base. Loose clusters of flowers. Usually needs support.
‘Spark’s Variety’ (syn. A. ‘Spark’, A. ‘Spark’s Variety’, A. ×cammarum ‘Spark’s Variety’), autumn monkshood, is summer blooming with branched clusters of amethyst-blue flowers on slender stems. 4 ft. Z5.
Aconitum napellus
• blue
• mid- to late summer
• 2–4 ft. × 1 ft.
• sun, part shade
• Z3–8
Common or English monkshood, helmet flower. Europe. Variable, but leaves are usually divided into five to seven lobes, and further cut into lance-shaped segments. Terminal racemes of indigo-blue flowers.
‘Album’ (syn. Aconitum napellus var. albidum) has spires of white flowers in midsummer. 3–4 ft. Z5–8.
‘Carneum’ (syn. A. compactum ‘Carneum’) has blush-pink flowers that intensify in color in cool, damp climates. 4–5 ft. Z2–8.
‘Rubellum’. Dark foliage shows off the spires of light pink flowers well. Best in part shade; may fade in intense sun. Good cut flower. 36 in. Z4–8.
Aconitum vulparia
syn. A. lycoctonum hort.
• yellow
• summer to early fall
• 3–5 ft. × 1.5 ft.
• sun, part shade
• Z3–6
Yellow wolfsbane, badger’s bane. Central and southern Europe. Long-stalked basal leaves diminish in size as they ascend the stem. Foliage is dark green, paler beneath, rounded or kidney shaped and cleft into five to nine divisions, each toothed and three lobed. Pale yellow, 0.75-in. flowers crowd into terminal racemes; blossoms rounded at the top and narrowed at the middle.
Other Notable Cultivars
‘Blue Lagoon’ is compact with bright blue flowers that open from the bottom up. Excellent as cut flowers. Mid- to late summer bloom. 10–12 in. Z4–8.
‘Blue Scepter’ is excellent for cutting and adapts well to shaded borders. Branching spires of white flowers broadly edged with purplish blue. 28 in. Z4–8.
‘Ivorine’ is compact, bushy, and erect with short, dense spikes of small, creamy-white flowers in early to midsummer. Best in part shade. 36 in. Z4–8.
‘Newry Blue’ has navy-blue flowers on erect stems. Comes true from seed. 4–5 ft. Z3–7.
‘Pink Sensation’ is a Piet Oudolf introduction with silvery pink flowers accented with a dark throat. No staking required. Best in sun. 36–40 in. Z3–8.
‘Stainless Steel’ bears metallic-blue flowers from early to late summer, with complementary grayish foliage. 40 in. Z2–9.
Polygonaceae
A genus in the making, Aconogonum includes a number of species that until recently were classified as Persicaria or Polygonum. Only one cultivar is garden worthy. See the entry for Persicaria for cultural notes.
Aconogonum ‘Johanniswolke’
syn. Persicaria polymorpha, Polygonum polymorphum
• white
• late spring to late summer
• 4–6 ft. × 4 ft.
• sun
• Z4–8
White dragon fleece flower, giant fleeceflower. High altitudes, gravelly soils, China and Japan. Develops large, vase-shaped clumps of vigorous, fleshy stems, but is not aggressive. Terminal panicles of white flowers that elongate into creamy-white plumes are long lasting, flush pink with age. Very good for cutting and a show stopper in the garden. Do not confine to small spaces as these plants like to strut their stuff. Better in cooler climates than in the hot and humid South.
Acoraceae
calamus, sweet flag
A handful of very ancient plants that were recently assigned their own family, sweet flags have traditionally been valued for the sweet smell produced when their leaves or rhizomatous roots were bruised or cut. Medieval housekeepers strewed sweet flag foliage on their floors as natural air fresheners; the leaves of some species were used as flavorings for beer.
These plants thrive in wet soils and even shallow water, making them invaluable for aquatic and bog gardens. Showier cultivars make attractive additions to damp beds, borders, and meadow plantings in areas where the soil remains reliably moist. The variegated cultivars are striking when grown in so-called miniature aquatic gardens—containers of soil topped with water. Effective as a substitute for ornamental grasses in shaded places where grasses fail. Sometimes attacked by rust and root rot. Seldom browsed by deer.
Propagate by division of the roots or start from seed.
Acorus americanus
• yellow
• late spring to summer
• 2–4 ft. high and wide
• sun, part shade
• Z4–7
Sweet flag. Northern half of North America. Vigorous and fast spreading, useful for stabilizing wet soils and as a groundcover in bog gardens and wet meadows. The lush sword-shaped leaves are green, though somewhat coarse; tiny, tawny-yellow flowers are borne in thumb-like spadices (dense flower spikes surrounded by a sheath or spathe), and are replaced in late summer and fall by dark berries. The foliage exudes a citrus fragrance when bruised. Acorus calamus is a closely similar European species sold by many nurseries, but it is invasive and should be avoided.
Acorus gramineus
• yellow
• late spring to early summer
• 0.5–1 ft. high and wide
• sun, part shade
• Z5–9
Japanese sweet flag. Eastern Asia. Semi-evergreen, produces tussocks of 0.25-in.-wide, grass-like leaves that smell of cinnamon; the tiny, yellow flowers are easily overlooked, though the red berries that follow are ornamental. A reliable but not-too-aggressive spreader, this species is most effective massed around the margins of ponds or along stream banks where it helps control erosion, or it can be used as an edging for moist borders. Japanese primulas, turtleheads, and cardinal flowers make fine companions. Occasionally subject to fungal leaf spot or rust, but usually no serious pest or disease problems; deer resistant. Early afternoon shade is beneficial in regions where sun is intense.
‘Minimus Aureus’ makes 3–4 in. × 6–9 in. tufts of yellow, grass-like foliage; insignificant greenish yellow flowers appear in spring.
‘Oborozuki’ (10–12 in.) and ‘Ogon’ (8–10 in.) are closely similar, compact, variegated cultivars with showy, green-striped, golden-yellow leaves.
Acorus gramineus ‘Ogon’
Ranunculaceae
baneberry
In recent years botanists have expanded the genus Actaea to include all the plants formerly classified as species of Cimicifuga (C. japonica, C. matsumurae, C. racemosa, and C. simplex). Many nurseries still sell these plants under their old names, so these have been included here as synonyms.
Natives of temperate Northern Hemisphere woodlands, baneberries flourish in moist, well-drained, humus-rich soils in situations of partial shade, dappled sunlight, or even full shade. Their combination of attractive foliage, small but elegant flowerheads, and ornamental fruits make them good choices for a woodland or wild garden. Those formerly classified as Cimicifuga are stately, elegant perennials, with lacy foliage and fluffy spires of sweetly scented, small, star-like flowers borne atop soaring, erect, or arching stems. All are intolerant of dry conditions but otherwise easy to grow, with few serious pests or other problems. Deer appear to ignore them. Typically long lived if their basic needs are met, actaeas often naturalize in hospitable locations.
Be warned that many members of this genus are poisonous in some or all their parts, especially the fruits (which are, however, attractive fare for many birds).
To propagate, sow seed in containers in fall and overwinter outdoors in a cold, but protected spot, or divide mature plants in early spring.
Actaea japonica
syn. Cimicifuga japonica
• white
• late summer
• 36–48 in. × 22 in.
• part shade, shade
• Z3–9
Japanese bugbane. Japan. Blooming later than most baneberries, this Japanese native has just three large leaflets per leaf and flowers borne in branching panicles. The best Actaea for the hot, humid southeastern United States.
‘Cheju Island Form’ is compact, making a mound of foliage just 12–14 in. high. Flower stems might reach 4–5 ft.; floriferous—a single mature plant may bear 12–15 flower spikes.
Actaea matsumurae
syn. Cimicifuga matsumurae, C. simplex var. matsumurae
• white
• late summer to early fall
• 3–4 ft. × 2–3 ft.
• part shade, shade
• Z4–9, HS
Bugbane. Central and eastern Asia. Chiefly available as the cultivar ‘White Pearl’ (syn. Cimicifuga simplex ‘White Pearl’). Arching, bottlebrush-like racemes to 24 in. long with small, white flowers borne on slender stems; these rise well above the mound of dissected, fern-like, medium green leaves that emerge late in spring.
Actaea pachypoda
syn. Cimicifuga pachypoda
• white
• mid- to late spring
• 1.5–2.5 ft. × 2–3 ft.
• part shade, shade
• Z3–8
White baneberry, white cohosh, doll’s eyes. Eastern North America. This low-key but charming woodland wildflower thrives under tree canopies and in clearings. Astilbe-like, compound leaves of three-toothed leaflets remain attractive all season. Sweetly scented, tiny, white flowers in oblong clusters are held aloft on long stems that turn red as the pea-sized, white berries, each with a single purple spot, develop. The berries do indeed resemble doll’s eyes but are extremely poisonous, making white baneberry a poor choice for households with children. The toxicity deters wildlife, so the fruit display lasts typically until a killing autumn frost. Ideal in woodland or shade gardens, as well as in shady borders. Long lived, it often naturalizes and forms colonies. Ferns, blue sedge, bugbanes, and goldenseal are good companions.
‘Misty Blue’ has delicate blue-green foliage together with white springtime flowers. Poisonous white berries follow. 2–3 ft.
Actaea racemosa
syn. Cimicifuga racemosa
• white
• late spring to early summer
• 4–6 ft. × 2–4 ft.
• part shade, shade
• Z3–8, HS
Black bugbane, black snakeroot, black cohosh. Rocky woods throughout most of the United States east of the Mississippi. Produces white-flowered spikes that may soar to 8 ft. in ideal conditions—humus-rich, evenly moist soil, and a sheltered, semi-shaded site. Astilbe-like foliage, three times divided, is an attractive deep green. Provide support for flower spikes, especially in windy spots.
Actaea rubra
• white
• mid- to late spring
• 1–3 ft. × 6–12 in.
• part shade, shade
• Z4–8, HS
Red baneberry. Cool, moist, nutrient-rich sites throughout the northeastern and midwestern United States, the Rocky Mountains, and Pacific Coast regions. Stems bear few coarsely toothed, deeply lobed leaves that emerge in a bushy clump. Clusters of lightly rose-scented, small, delicate, white flowers open above the foliage; conspicuous glossy red or occasionally white berries follow in late summer and fall. The fruits are favorites of many birds, including grouse, gray catbirds, and robins. Best in woodland gardens where trilliums, meadow rues, gaultheria, and false Solomon’s seal are appropriate native companions.
Actaea simplex
syn. Cimicifuga simplex, C. ramosa
• white
• late summer to early fall
• 3–4 ft. × 2–3 ft.
• part shade, shade
• Z4–8, HS
Bugbane, Kamchatka bugbane. Mongolia, eastern Russia, and Japan. Late in the season numerous, small, creamy-white, strongly scented flowers bloom in fluffy spires atop tall, upright, wiry stems. Attractive dark green, astilbe-like foliage, compound with deeply cut leaflets. Often self-seeds and naturalizes. Provide support for flowering stems; best where sheltered from strong winds. Bugbane is an asset in woodland gardens, among shrubs, in cottage gardens, and naturalized areas. Most attractive when planted in multiples; white spires show up well against dark backgrounds.
Atropurpurea Group (black bugbane) includes a number of dark-leaved cultivars that are still listed in many catalogs under Cimicifuga ramosa: ‘Atropurpurea’, 6 ft.; look for clones with darker-hued foliage. ‘Black Negligee’ is vigorous, with deeply cut, black-purple foliage on dark stems and bottlebrushes of purple-tinged, white flowers; to 5 ft. ‘Brunette’ has bronze-hued foliage to set off the white, sometimes pink-tinged wands of flowers, each about 8 in. in length. Fragrant ‘Hillside Black Beauty’ has black stems up to 7 ft. that bear white flowers; dark, coppery-purple foliage. ‘James Compton’ is compact with deep bronze foliage and white, sometimes pink-tinged flowers; its clumps are 2–3 ft. × 1.5–2 ft.
Campanulaceae
ladybells
Like other members of the bellflower family, ladybells are noted for their spikes of dangling, bell-shaped, blue or violet flowers that furnish long-lasting color to the middle and back of a border. Branched, upright stems bear mostly alternate stem leaves with toothed margins. The thick roots resent disturbance. Ladybells thrive in sun if their roots remain moist, or in partly shaded, damp places. Soil should be high in humus with good drainage. For neatness and to prevent self-seeding, remove spent blooms as they fade. Lovely in lightly shaded woodlands, in borders, or among shrubs. Appropriate companions for shaded spots include lady’s mantle, hostas, and hellebores; in sun, tickseeds and beardtongues make attractive partners. In addition to the species described here, others, including Adenophora pereskiifolia, bear mention but are not readily available.
Not browsed by deer or rabbits, but slugs and snails may be a problem.
Propagate by seed sown indoors (do not cover) in late winter through early spring, by basal cuttings taken in early spring, or by root cuttings taken in winter.
Adenophora bulleyana
• pale blue
• late summer
• 3–4 ft. × 1–1.5 ft.
• sun, part shade
• Z3–8
Ladybells. Western China. Upright with lustrous, mostly basal leaves, serrated along the edges and wider than those of other species. Spires of dainty, 0.5-in., pendulous flowers are often grouped in threes on the stem; attractive light to medium blue, bell-shaped flowers. Valued not only for its charm, but also for its time of flowering with late garden phlox, agastaches, and lantanas.
Adenophora bulleyana
Adenophora confusa
syn. A. farreri
• blue
• late spring
• 24–36 in. × 24 in.
• sun, part shade
• Z3–7
Common ladybells. China. This plant is similar to and often confused with creeping bellflower (Campanula rapunculoides), which is a roving thug and extremely difficult to eliminate. To ascertain whether you have the correct species before planting, tear a flower apart and look closely; ladybells have a noticeable thick basal disk at the base of the style. Deep blue, bell-shaped flowers about 0.75 in. long. Fleshy roots are difficult to divide, but pencil-thick ones may be used for root cuttings. Group in the border or naturalize in light woodlands. White or pale pink astilbes provide an attractive contrast in light shade; use yellow-foliaged evergreens or shrubs such as European elder (Sambucus racemosa ‘Sutherland Gold’) as a backdrop. Best planted in groups for impact.
Adenophora liliifolia
syn. A. communis
• blue
• summer
• 18–24 in. × 24 in.
• sun, part shade
• Z3–9
Lilyleaf ladybells. Europe. Not quite as tall as Adenophora confusa, but equally lovely. However, roving roots spread rapidly and must be contained unless in a naturalistic setting. The branched stems are hairy, clothed with lance-shaped leaves and topped with spikes of fragrant, nodding, lavender-blue bells. Tolerates heat and humidity well—the best species for warm southern gardens.
Other Notable Cultivars
‘Amethyst’ (‘Amethyst Chimes’), possibly a hybrid of indeterminate parentage, is well behaved and produces erect, tall, leafy stems. From late spring to midsummer these are topped with loose spikes of lightly fragrant, pendulous, flaring, bell-shaped flowers of amethyst blue. In sun or part shade this clump former spreads only slowly and is best left undisturbed, especially where the plants can naturalize. A good cut flower. 18–36 in. × 12–24 in. Z3–8.
Ranunculaceae
pheasant’s eye
What a joy to see the bright yellow, buttercup-like flowers of pheasant’s eye opening above its cluster of ferny leaves in late winter. Named for the god of beauty and desire in Greek mythology, Adonis flowers make outstanding additions to rock gardens, shaded woodland edges, under deciduous trees, or in raised beds and containers. Of the 20 or so species, several are annual and not covered here.
Cupped or spreading flowers, borne on branched or unbranched stems, are mostly yellow, terminal, and solitary, with petal-like sepals and up to 30 petals. Double forms are sterile and must be increased by division. The alternate, fern-like leaves are triangular in outline and three-times divided; each toothed lobe is lance shaped.
Pheasant’s eyes prefer humus-rich, well-drained soil in a cool, partly or fully shaded spot (especially in hot southern gardens). Plant several together to make an impact; they bulk up slowly. Mulch with pine needles through the winter. Seldom browsed by deer, but often attacked by slugs and snails and should be protected from them.
Divide the rhizomatous roots of established plants in early to midsummer, or collect and sow fresh seed as soon as it ripens after bloom—usually when the foliage begins to die down into summer dormancy.
Adonis amurensis
syn. A. dahurica
• yellow
• late winter to early spring
• 6–9 in. × 12 in.
• part shade
• Z4–7
Pheasant’s eye, Amur adonis. Manchuria, Korea, Japan. Perhaps the earliest species to bloom, it produces its cupped, 1- to 2-in., yellow flowers (brown in the bud) as soon as winter temperatures moderate. Clumps of dissected foliage appear when the flowers are open, going dormant by early summer. Mark the spot where they grow to avoid damage from cultivation through the season. Below are a few of the exciting cultivars on the market; for more, check Japanese nurseries, including the Rare Plant Nursery and Shikoku Garden.
‘Fuku Jukai’ is semi-double, with 2-in.-wide, yellow flowers. Early. 6 in.
‘Pleniflora’ (‘Plena’) has double, yellow buttercups, with raggedy petals flecked with green at the center. 6 in.
‘Sandan Zaki’ (“three-step blooming”) is similar to ‘Pleniflora’ but has four alternating layers of frayed, yellow and green petals. Sterile and possibly hard to find, but quite a gem.
Adonis amurensis
Adonis vernalis
• yellow
• early spring
• 9–12 in. × 6 in.
• part shade
• Z4–7
Spring adonis, pheasant’s eye. Europe. Somewhat later to bloom than Adonis amurensis, spring adonis is also slightly hardier. Stems are not branched and most of the finely dissected, 1- to 2-in.-long leaves lack petioles. The spreading, butter-yellow flowers, 2–2.5 in. across, flatten their petals to the sun. Dress with limestone chips if soil is strongly acid. Very slow to bulk up.
Brassicaceae
stonecress
Most of the 40 or so low-growing stonecresses are typically relegated to rock gardens or stone walls, although several are superb at the front of the border or along pathways where their abundant bloom sparkles.
These evergreen or semi-evergreen shrublets blanket themselves with clusters of four-petaled, 0.25-in. flowers in spring. They do best in full sun in very well-drained, preferably sweet soil. Add lime if necessary or provide a mulch of lime chips around the crown. Shear after bloom time to encourage vegetative growth. Pest and disease free, except for crown rot in damp soils.
White-blooming Aethionema iberideum grows to only 6–9 in., but blooms abundantly. It does not tolerate hot, humid weather; difficult to find outside of alpine specialists circles.
Increase by soft cuttings in late spring or from seed in spring.
Aethionema armenum
• pink, white
• spring to early summer
• 8–12 in. high and wide
• sun
• Z5–7
Turkish stonecress. Caucasus and Turkey. This short-lived evergreen or semi-evergreen subshrub bears linear, gray-green leaves to 0.5 in. long. Dense, terminal clusters of pale pink, cruciform flowers cover the plant for several weeks. Reseeds generously. Best in raised beds, tumbling over a wall, or in rock gardens where drainage is perfect. Small spring bulbs, including grape hyacinths, squills, and tulips, are good springtime companions, perhaps followed by dwarf bellflowers. Deer seem to avoid it, at least in the Sierras.
‘Warley Rose’. Possibly a hybrid, this 4- to 6-in.-tall beauty may spread to 24 in. across, and looks best massed as a groundcover or as a specimen plant among other low-growing plants. Abundant clusters of dark pink flowers rise above the mass of blue-green leaves.
‘Warley Ruber’ has almost maroon flowers. Z6–8.
Aethionema coridifolium
syn. A. coridifolia
• pink
• early summer
• 6–10 in. × 12–15 in.
• sun
• Z4–8
Lebanon stonecress. Lebanon. Upright grower that forms mounds of unbranched stems with slender, fleshy, bluish green leaves. Flower stems are crowned with 1-in. clusters of lavender or dusty pink flowers. May self-sow in good conditions especially when mulched with gravel or stone chips.
Aethionema grandiflorum
syn. A. pulchellum
• pink
• late spring to early summer
• 12–18 in. × 18 in.
• sun
• Z5–9, HS
Persian stonecress. Western Asia, Caucasus. Upright, shrubby, and evergreen with grayish, needle-like leaves; the largest of the genus, suitable for the front of flower borders. The loose clusters of delicately veined, pink blooms are showy, even suitable as cut flowers. Add lime especially to clay soils to raise the pH and break up the clay. A full-sun position with free drainage as found between pavers and surrounding patios is ideal. Drought tolerant and appropriate for xeriscapes. Shear lightly when blooms are spent to prevent abundant self-seeding, as well as to shape. Perennial candytuft (Iberis sempervirens) is an attractive companion requiring similar cultural conditions. Protect from browsing deer.
Lamiaceae
giant hyssop
An old-fashioned favorite, Agastache is ideally suited to modern gardens. The various species have much of the vigor and toughness of their mint relatives but with little of the invasiveness that make the mints so problematic. Agastache flowers are pretty and sweet scented but for the most part modest. Although they don’t grab the eye like some of their more flamboyant fellows, they are borne over a long season, typically from midsummer to early fall when blooms of any kind are scarce in perennial gardens. They also attract a steady stream of hummingbirds, butterflies, and other pollinators. Foliage is usually aromatic on sturdy stems that rarely require staking. They fit easily into a wild or meadow garden.
Though occasionally subject to powdery mildew, agastaches are typically pest free and notably resistant to grazing deer and rabbits. They flourish in a wide range of well-drained soils, though are likely to live short lives on damp clays. Small wonder then that this traditional standby is receiving renewed attention from plant breeders, who have introduced a host of fine new cultivars in recent years.
A natural for butterfly gardens, agastaches also make good companions for roses—the fragrances are complementary and the well-furnished foliage of giant hyssops masks the rose’s leggy stems. Likewise, their spires of blossoms make agastaches useful as visual punctuation for summertime mixed borders. The drought tolerance of the western US species makes these North American natives perfect for xeriscapes. Encourage rebloom by routine deadheading
Propagate by seed or division, or by taking semi-hardwood and softwood cuttings just as flowering is about to begin.
Agastache cana
• pink
• early summer to midfall
• 24–36 in. × 18 in.
• sun, part shade
• Z5–9, HS
Texas hummingbird mint. Texas and New Mexico. Long-blooming spikes of fragrant, raspberry-pink flowers borne above aromatic, gray-green foliage. Drought tolerant but will not stand wet feet or humidity.
Agastache foeniculum
• lavender, purple
• midsummer to early fall
• 2–4 ft. × 1.5–3 ft.
• sun, part shade
• Z4–8
Giant blue hyssop. Native to fields, prairies, and woodland openings throughout the upper half of North America. This perennial grows well on moist, well-drained soils, but once established also tolerates dry soils. Unlike most agastaches, giant blue hyssop copes well with humidity. The flowers are borne in whorls around the square stems, stacked one on top of the other in tall spikes. The anise-scented foliage may be dried for use in teas; flowering stems add color as well as fragrance to cut-flower arrangements.
Agastache foeniculum
‘Golden Jubilee’ bears young foliage that is yellow to chartreuse, maturing to lime green.
Agastache rugosum
• violet-blue
• midsummer to early fall
• 4 ft. × 1.5 ft.
• sun, part shade
• Z5–9
Korean hyssop. Introduced into the nursery trade by plant collector Dan Hinkley, this Asian native balances its long-blooming, violet-blue flowers with glossy, deep green, intensely mint-scented foliage. Like Agastache foeniculum, this species tolerates humidity.
‘Honey Bee Blue’ bears blue flowers with gray-green foliage.
Agastache rupestris
• orange
• midsummer to early fall
• 1–3 ft. high and wide
• sun
• Z5–9, HS
Rock anise hyssop. West Texas and Mexico. A combination of orange and yellow blooms edged with magenta and pink and licorice-scented, silvered foliage makes this species the showiest of the bunch. It is notably drought tolerant, but is likely to fall prey to fungal infections where summers combine heat with humidity.
‘Acapulco Salmon and Pink’ bears mint-scented foliage and spikes of large, bicolored orange-and-pink flowers. 24–30 in. × 15 in. Z5–10.
‘Black Adder’ displays spikes with stacked whorls of smoky red-violet blossoms all summer and into early fall. 2–3 ft. × 1.5–2 ft. Z6–9.
‘Blue Fortune’ produces tall spikes of powder-blue flowers. 3–4 ft. × 1.5 ft. Z5–9.
Agastache ‘Blue Fortune’
‘Firebird’ has spikes of mixed copper, coral, and red flowers. 4 ft. × 2 ft. Z6–9.
‘Heatwave’ has plenty of deep hot-pink spikes on tight, clumping plants. Tolerates heat and humidity. 36 in. in bloom. Z5–10.
‘Tutti Frutti’ (Agastache barberi × A. mexicana) bears large, deep pink flowers over a mound of grayish foliage. 2–3 ft. × 1–2 ft. Z6–9 in the east, Z6–10 in the west.
Asteraceae
white snakeroot
Formerly classified with the eupatoriums, white snakeroot has been moved to its own genus. This native is excellent in wild or native plant gardens where it attracts bees and butterflies.
Ageratinas appreciate soil rich in organic matter, and require moderate but regular irrigation while young for the best bloom. However, plants tolerate drought once established. Staking is seldom necessary. A good cut flower. Seldom browsed by deer; combine with other deer-resistant natives, including goldenrods and asters.
Propagate by dividing mature clumps in late winter or spring, by seed, or by stem cuttings taken in spring.
Ageratina rugosus
syn. Eupatorium rugosum
• white
• midsummer to early fall
• 3–5 ft. × 2–3 ft.
• sun, part shade
• Z4–8
White snakeroot. Eastern half of North America. Large, coarsely toothed, heart-shaped leaves borne on strong, branching stems; the small, pure white flowers are carried in flat-topped, branching clusters. Tolerant of partial shade—the most shade tolerant of the genus, in fact. Leaf miner may cause unsightly, white-traced leaves. This plant is toxic if consumed in quantity.
‘Chocolate’ (syn. Ageratina altissima ‘Chocolate’), an introduction of the Mt. Cuba Center, has striking maroon-brown foliage and chocolate stems.
Asteraceae
silver-and-gold
This genus in the daisy family has only one species of interest to gardeners. It was formerly lumped with chrysanthemums and later dendranthemas, but due to the considerable rearranging of genera of that clan, it now has its own genus.
It is valuable as a fine specimen plant, and does well in containers.
Ajania pacifica
syn. Chrysanthemum pacificum, Dendranthema pacificum
• yellow
• fall
• 1–2 ft. × 1–3 ft.
• sun, part shade
• Z5–9
Silver-and-gold. Asia. A fine plant prized as much for its attractive foliage as for its branched clusters of showy, fall-blooming, bright yellow button flowers. Neat, rounded mounds of stems are clothed with lobed, light green, 1- to 2-in. leaves, each accented with a crisp silver edge, and hairy, silver undersides. Pinch young growth in early summer to encourage bushy plants. Best where soil is average to even poor, but drains well. Somewhat tolerant of drought, vulnerable to wet winter soils. Silver-and-gold is appropriate in the foreground of beds and borders, among low evergreens, even massed as a 1-ft.-tall groundcover or as an attractive skirt for specimen trees. Striking companions include colorful yellow tickseeds, trailing Dichondra ‘Silver Falls’, variegated ivies, or golden bidens. Seldom browsed by deer, but slugs and snails may be a problem. Occasionally attacked by white rust; locally prohibited in areas prone to that disease. Terminal cuttings root easily from new spring growth.
Ajania pacifica
‘Pink Ice’ (pink ice daisy) is probably a hybrid with garden chrysanthemums. It has very short, pink ray flowers surrounding the central yellow disk.
‘Yellow Splash’ has yellow-variegated foliage and yellow flowers.
Lamiaceae
bugleweed
Bugleweeds have gotten a bad rap for being invasive. They certainly can be a nuisance when spreading into your lawn, but in a spot where their spread can be controlled, their vigorous growth makes them ideal groundcovers.
Bugleweed foliage is attractive—the undivided leaves are borne in opposite pairs on square stems, and superior cultivars offer evergreen, colored, sometimes textured leaves that provide interest all year. In late spring and early summer bugleweeds bear terminal spikes of small, two-lipped, brilliant blue, pink, or white flowers carried in tiered whorls (verticillasters) up the stem.
Tolerant of most moisture-retaining soils, bugleweeds benefit from the addition of organic material, such as compost or well-rotted leaves, at planting time. Shaded and partly shaded sites are ideal, although where sun is not intense they thrive in full sun. Maintain vigor by dividing in spring or fall every two to three years. Common bugleweed, in particular, is inclined to invade and overcome lawns; plant where their invasive tendencies are an asset on the edge of woodlands, along shaded pathways, and on difficult shaded banks to control erosion. Other species adapt well to planting at the front of beds and borders, under shrubs, and even in containers. The flowers attract hummingbirds and butterflies. Sometimes susceptible to crown rot under hot, humid conditions; infected plants die out rapidly. Deer resistant.
Propagate named cultivars by division or detach the stolons in midsummer after blooming; start species from seed sown in late summer to Thanksgiving for germination the following spring.
Ajuga genevensis
syn. A. alpina, A. rugosa
• various
• early summer
• 6–15 in. × 9 in.
• sun, part shade, shade
• Z4–9
Geneva bugleweed, blue bugleweed, upright bugleweed. Southern Europe. The erect stems of brilliant blue flowers are especially eye-catching massed as a groundcover. The glossy dark green, 3- to 5-in.-long leaves are often hairy, toothed, or lobed along the edges. This species tolerates dryer soil conditions. Plant spring-blooming bulbs between the clumps in fall and enjoy a colorful vignette each spring.
‘Alba’ has white flowers.
‘Pink Beauty’ has pink flowers on 4- to 8-in. stems.
‘Variegata’ has white-mottled leaves. Not as vigorous as others of its kind.
Ajuga pyramidalis
syn. A. metallica
• blue
• spring to early summer
• 6–12 in. × 12 in.
• sun, part shade, shade
• Z5–9
Pyramidal bugleweed. Central Europe. The dense, pyramidal flower spikes give this species its name. Clumps of basal rosettes of slightly toothed leaves thrive in damp, moisture-retentive soil but seldom spread much due to the lack of stolons common to other species.
‘Metallica-Crispa’ (‘Crispa’, ‘Metallica-crispa Purpurea’, ‘Min Crispa Red’) has lustrous reddish brown leaves, crisped along the edges. Best leaf color is displayed in sun, where it is a fitting companion for low, silvery artemisia. Short spikes of blue flowers. 6 in. tall.
Ajuga reptans
syn. A. repens
• blue
• late spring to early summer
• 2–12 in. × 9–12 in.
• sun, part shade, shade
• Z3–9
Common bugleweed, carpet bugleweed. Europe, Japan. This sturdy evergreen perennial creeps rapidly by stolons to develop large patches, sometimes up to 36 in. across. It is excellent as a dense groundcover—a few cultivars even tolerate light foot traffic. Spoon-shaped, dark green leaves, with 3.5-in.-long, spikes of dark blue flowers. Mow spent flower spikes after bloom time, or trim with a string trimmer or hedge shears. Slugs may be a problem, along with perhaps southern blight, fungal leaf spots, and crown rot. Tolerates deer and rabbits.
Cultivars abound; this is a brief selection:
‘Black Scallop’ (‘Binblasca’) has fast-spreading rosettes of glossy, crinkled dark maroon foliage, with best color in sunny spots. Brilliant rich blue flowers. Excellent weed-suppressing groundcover. Provide good air circulation in hot, humid regions. 4–6 in. Z4–9.
‘Bronze Beauty’ (‘Atropurpurea’, ‘Purpurea’) has deep bronzy purple foliage in sun; dark green in shade; deep blue flowers in late spring. Tough and drought tolerant. Spreads freely. 3 in. tall.
‘Burgundy Glow’ has eye-catching tricolored leaves of creamy white, rosy plum, and dark green. Not as aggressive as some, this cultivar is appropriate for rock gardens and as edgings. ‘Multicolor’ is darker-leaved. 6 in. tall.
Ajuga reptans ‘Burgundy Glow’
‘Catlin’s Giant’ is larger than other cultivars. Spikes of blue flowers to 8–12 in. above rosettes of bronzy, 6-in., spinach-like leaves. 3–12 in. Z4–8.
Ajuga reptans ‘Catlin’s Giant’
Chocolate Chip (‘Valfredda’) is extremely dwarf and less aggressive. Tight, 2-in.-high mats of narrow, crinkled, deep chocolate–colored leaves accented with maroon; best color in sun; spikes of blue flowers. Attractive planted between pavers and stepping stones. 3 in. Z4–9.
‘Planet Zork’. Spoon-shaped, crinkled leaves that are cupped to expose a light-colored rim from beneath. Tolerates heat and humidity. 2 in. tall.
‘Silver Beauty’ has rosettes of waxy, gray-green leaves, irregularly edged with cream. Withstands light foot traffic. Blue flowers. 4 in. tall.
Other Notable Cultivars
‘Brockbankii’ is a hybrid of Ajuga genevensis × A. pyramidalis. Almost a dwarf form.
syn. Althaea
Malvaceae
hollyhock
No cottage garden is complete without hollyhocks, which are known for their graceful, stately spires of blossoms and are among the best loved and most evocative of flowers. The cup-shaped, sessile, or nearly stalkless flowers arrange themselves in racemes around a central stem that in ideal conditions—full sun, good air circulation, moist, well-drained soil, and a dry climate—may soar to a height of 10 ft.
In less than ideal conditions, however, especially in moist, humid climates, hollyhocks are likely to prove martyrs to rust, a fungal infection. Prevention of rust is easier and more effective than controlling an outbreak; buy only disease-free plants, or start rust-resistant types from seed. Clean up thoroughly in late fall to prevent rust spores from overwintering onsite.
Hollyhocks are also subject to attack by slugs, snails, and spider mites, as well as Japanese beetles, but they are seldom browsed by deer. Staking is necessary to support the taller cultivars. Though not long lived, hollyhocks are more persistent if cut to the base after blooming; leave a stalk or two to set seed to be assured of volunteer seedlings the next spring.
With this minimal care, hollyhocks provide a spectacular backdrop to shorter perennials and make dramatic cut flowers. One of the few plants that flourish in the root zone of black walnut trees. The blooms attract hummingbirds and butterflies.
Propagate by seed.
Alcea ficifolia
• various
• midsummer to early fall
• 6–8 ft. × 2–3 ft.
• sun
• Z3–9
Fig-leaf hollyhock, Russian hollyhock. Siberia. As the name indicates, the leaves of this species are deeply cut, “fingered” like the leaves of a fig. The white, yellow, copper, pink, or red flowers are single, to a diamater of 3 in. Rust resistant.
Happy Lights is a seed strain in the full range of flower colors; late-winter-sown seeds produce plants that bloom the first year.
Alcea rosea
syn. Althaea rosea
• various
• midsummer to early fall
• 6–8 ft. × 1–2 ft.
• sun
• Z3–10, HS
Hollyhock. Turkey, Asia. The classic hollyhock of Old World cottage gardens. Only those in dry, sunny climates should expect good results.
Countless strains and cultivars are available, including:
Chater’s Double Hybrids include double powder-puff flowers in a full range of mixed or individual colors.
‘Crème de Cassis’ bears 3- to 4-in., single or semi-double, black currant–colored flowers edged with paler rose. 4–6 ft.
Majorette Mix is a dwarf strain. Double or semi-double flowers in whites, yellows, pinks, and reds. 24–30 in. × 12 in.
Powder Puffs Mix has white, yellow, rose, or red, fully double flowers to 4 in. across.
‘Sunshine’ has large, single flowers of sunny yellow. 5–6 ft. Z3–9.
Alcea rosea is perfect for cottage gardens
Alcea rugosa
• yellow
• midsummer to early fall
• 6–8 ft. × 2–3 ft.
• sun
• Z3–9
Russian hollyhock. Ukraine. Furrowed, gray-green leaves are cleft into five lobes. Hairy stems carry single, 4-in., butter-yellow flowers. Rust resistant.
Rosaceae
lady’s mantle
Lady’s mantles, particularly Alchemilla mollis, are among those cottage-garden perennials that people often remember with nostalgia from their childhood. Indeed, the softly hairy, lobed, and pleated leaves that hold a drop of rain or dew like a pearl, and the froth of tiny chartreuse flowers are irresistible. The name of the genus refers to the belief that the beads of water held by the leaves were “celestial water,” pure enough to be used by alchemists trying to turn base metals into gold.
Only a few species are cultivated. Alchemillas do best in shade or part shade, especially when grown in warm regions. Avoid planting sites in intense sun. Soil should be humus rich and moisture retentive; leaves may burn if allowed to dry out. Low maintenance, except for deadheading to control promiscuous self-seeding. Cut back shabby foliage to the crown; fresh new growth will appear in a few weeks. The flowers can be enjoyed as fresh cuts or dried for later use; the leaves serve as attractive filler in flower arrangements. Air-dry flower sprays by hanging them upside down in bunches in a cool, well-ventilated place.
Lady’s mantle is excellent as edging along pathways or massed as a groundcover, perhaps broken up with sweeps of hardy geraniums, hostas, or lilyturf. It is valued in partly shaded beds and borders; appropriate partners include grape hyacinths, daffodils and other spring bulbs, astilbes, toad lilies, and Japanese anemones. Partner smaller species in rock gardens with rock cress, perennial candytuft, and low-growing herbs such as thymes. Deer and rabbits seldom browse, but slugs and snails attack young seedlings; a light scattering of fish tankage or turkey gravel deters them.
Divide established or overgrown plants in early spring every three to five years as growth commences; discard worn out pieces. Sow seed in spring.
Alchemilla alpina
• green
• early summer
• 3–8 in. × 20 in.
• sun, part shade
• Z3–7
Mountain lady’s mantle. Alpine regions of Europe. A diminutive plant with 2-in., deeply lobed, sharply toothed leaves, rimmed with silvery hairs that also blanket the underside. Loose sprays of frothy flowers rise on 3-in. stems. Excellent in rock gardens or between pavers. Alchemilla conjecta is similar but may reach 16 in.; A. ellenbeckii (Z5–7) rises only a few inches with deeply lobed, 1-in. leaves, hairy on both sides. Plant with creeping thymes and mazus.
Alchemilla erythropoda
• yellow green
• late spring to late summer
• 6–12 in. × 8 in.
• sun, part shade
• Z3–7
Red-stemmed lady’s mantle. Mountains of Turkey and Russia. This “mini-mollis” gets a red tinge to its stems in full sun. The leaf stems or petioles are covered with fine hairs and both sides of the bluish green, shallowly lobed leaves are also velvety. Excellent for troughs, rock gardens, and where space is limited.
Alchemilla mollis
• green-yellow
• late spring to early summer
• 18–24 in. × 24 in.
• sun, part shade
• Z3–8
Lady’s mantle. Turkey and Carpathian Mountains. This, the most widely grown of the lady’s mantles, has light green, velvety leaves to 6 in. across, pleated into 7 to 11 lobes, and serrated along the rim. Airy sprays of 0.25-in., greenish yellow, petal-less flowers in early summer. Deadhead routinely to prevent self-seeding; excessive self-seeding of lady’s mantle has resulted in it becoming almost invasive in some places. Keep soil moist. Lady’s mantle is charming as an underplanting for pink roses, and a fine companion for cottage garden flowers: foxgloves, hollyhocks, iris, and bellflowers.
Alchemilla mollis is possibly a synonym for common lady’s mantle, A. vulgaris; reportedly A. vulgaris has a somewhat looser habit.
‘Robusta’ is an upright clumper, more full bodied and with larger leaves than the species. Yellowish green flowers in early summer, repeating later in the season. Tolerates heavy clay soil and drought when established. 15 in. × 36 in.
‘Senior’ grows to about 10 in. × 28 in.
‘Thriller’ is more compact. Green-flowered inflorescences to 9 in. across. 14 in. × 30 in.
Alchemilla mollis
Amaryllidaceae
onion
This enormous and cosmopolitan genus ranges throughout temperate regions of the Northern Hemisphere, with a handful of species from Central and South America, and also Africa. Within this range, alliums have adapted to habitats as diverse as sandy uplands and lowland swamps, though most prefer well-drained, even droughty sites.
Alliums include several staples of the kitchen garden, including onions, garlics, shallots, leeks, and chives. Their blooms may be less familiar in the flower garden, but they are, nonetheless, as essential in their own way as their edible relatives. Their ability to store energy in their bulbs makes alliums nearly invulnerable to seasonal drought—many species grow best where summers are hot and dry—and helps them weather all sorts of other adverse conditions. Furthermore, the sulfur-based chemicals that give alliums their pungent aroma act as repellents to deer, rabbits, and rodents, even many insect pests. Be alert for onion flies and thrips, however. Wet soils, especially during dormancy, may cause bulbs to rot.
Typically allium leaves are long and cylindrical (think chives) or strap shaped (think leeks), and though attractive enough when fresh and green, they grow tattered and flop as the season progresses. Accordingly, plant alliums in fall among bushy flowers or ornamental grasses that will hide the alliums’ aging foliage; such neighbors will also help to support the alliums’ naked scapes (flower stalks). Small individual flowers are borne in umbels, radiating clusters that collectively look like bright, botanical starbursts. Most bloom is in late spring or early summer, neatly bridging the June gap, the temporary dearth of bloom that afflicts perennial gardens after most spring bulbs are spent and before the summer perennials do their stuff.
Planted in groups along the length of a border, alliums’ sculptural flowers add a visual rhythm to any design. Allium flowers attract nectar-foraging butterflies and bees; many ornamental onions make elegant cut flowers.
To propagate alliums, lift and divide the clumps of bulbs when dormant, or start from seed—many alliums are prolific seed producers and surround themselves with hosts of volunteer seedlings without any encouragement from the gardener.
Allium aflatuense
syn. A. hollandicum
• purple
• late spring
• 3–4 ft. × 6 in.
• sun
• Z3–8
Purple ornamental onion. Iran. Baseball-sized heads of brilliant purple, tiny, starry flowers rise on tall scapes. Typical bluish, strappy foliage that begins to die back at bloom time. Pastel-colored German irises, silvery catmints, and wormwoods are compatible bedfellows; a skirt of lady’s mantle camouflages fading leaves.
‘Purple Sensation’ is more widely grown than the species; plant in groups of 10 to 12 for a real impact. Fortunately, the bulbs are not expensive.
Allium aflatuense ‘Purple Sensation’ makes a vibrant splash of color in a late spring border
Allium atropurpureum
• dark purple
• late spring
• 12–24 in. × 4 in.
• sun
• Z3–8
Ornamental onion. East Asia to northern India. So dark is the purple of this allium’s star-shaped flowers, that the densely packed, tennis-ball-sized umbel looks almost black. They pose a dramatic contrast to the blossoms of lighter colored relatives such as hybrid ‘Mont Blanc’ and a complement in form as well as color to the simultaneous flowers of ‘Sooty’ sweet William.
Allium bulgaricum
syn. Nectaroscordum siculum subsp. bulgaricum
• cream, maroon
• late spring to early summer
• 24–36 in. × 6–8 in.
• sun, part shade
• Z5–10
Sicilian honey lily. This Mediterranean native requires regular irrigation through its period of growth until the end of bloom time, but thereafter prefers a drier soil. The parasol of pendulous, 0.5- to 1-in. flowers measures 4 in. or more across, with individual cream flowers, striped with maroon and touched with green. Baptisias and tall bearded irises, which bloom at the same time, make good companions.
Allium bulgaricum
syn. A. azureum
• blue
• early summer to summer
• 12–36 in. × 6–12 in.
• sun
• Z3–9, HS
Blue globe onion. This Asian native blooms a couple of weeks later than Allium atropurpureum or A. bulgaricum, and provides one of the few true blues of the early summer perennial garden. The flowers are borne in 1-in., spherical clusters; the leaves die back before the flowers emerge. An asset to cottage, meadow, and rock gardens, this onion blooms simultaneously with herbaceous peonies; its exquisite flowers contrast handsomely with the peonies’ lush blooms.
Allium cernuum
• pink
• early to late summer
• 12–18 in. × 6–8 in.
• sun, part shade
• Z3–9
Nodding onion, lady’s leek. Dry clearings, rock outcroppings, and prairies in mountainous regions from Canada to Mexico. Nodding onion produces its loose umbels of drooping, pink or white flowers atop scapes that bend downward at the top, possibly to restrict the variety of pollinating insects. The strappy leaves are flattened and solid, with a small ridge along the length. Very easy to grow, nodding onion seeds about unless deadheaded, but never becomes aggressive. The bulbs sometimes produce offsets, creating clumps. Tolerates a wide range of well-drained soils; drought tolerant when established. Attractive with beebalms, black-eyed Susans, and milkweeds in native, meadow, or wild gardens.
Allium moly
• yellow
• late spring
• 9–18 in. × 6–9 in.
• sun, part shade
• Z3–9, HS
Lily leek. Southern Europe. Starry, greenish yellow flowers are borne in loose, 2-in.-wide clusters. In average, well-drained soil and full sun (avoid intensely sunny spots) this species naturalizes, forming extensive colonies readily, though it isn’t an aggressive invasive.
‘Jeannine’ is a superior selection that bears two scapes per bulb, topped with golden yellow flowers.
Allium moly
• rose-purple
• late spring
• 12–36 in. × 12–18 in.
• sun
• Z7–9
Schubert onion. This native of the eastern Mediterranean and central Asia bears spherical, starburst heads of flowers, 1 ft. or more in diameter, which are guaranteed to stop traffic. One of the best alliums for hot southern regions, Allium schubertii overwinters successfully in zones 5–6 given well-drained soil and tucked in with an insulating mulch of straw or evergreen boughs in late fall. Enjoy the blooms in your garden, allow them to go to seed and dry, then bring them indoors to serve as focal points of dried arrangements.
Allium senescens
syn. A. montanum
• pink
• mid- to late summer
• 9–24 in. × 12 in.
• sun
• Z4–10
German garlic, broadleaf chives. Europe, northern Asia. Bulbous with short rhizomes that make vigorous, but not invasive, clumps. Strappy basal leaves, 2–12 in. long; dense, 0.75-in. umbels composed of 20 or more fragrant, cup-shaped flowers last for several weeks. Suitable for rock gardens and atop retaining walls.
‘Blue Twister’ was selected for its unusual bright blue, twisted leaves. Deadhead routinely to extend bloom. 12 in. Z3–8.
‘Glaucum’ (subsp. glaucum) has interesting clumps of twisted, bluish gray foliage. Lavender-pink heads of flowers rise above the foliage mass. Decorative even when not in bloom.
Allium senescens
Allium thunbergii
• reddish violet, white
• fall
• 18–24 in. × 10 in.
• sun, part shade
• Z5–8
Japanese onion. Japan. This underused species deserves a wider audience, if only for its late bloom time. Through the season, slightly untidy tufts of mid-green, grassy foliage, triangular in cross section, mark their spot. In late summer, sturdy, 8- to 9-in. scapes are topped with small, green buds the shape of dunce caps; these enlarge and open to 1- to 2-in.-wide globes of numerous reddish violet flowers with slender exserted stamens and styles that produce a dainty appearance. Foliage takes on orange hues after the first hard frost. Flowers dry well and if left on the plant remain decorative as the flowers fade to deep pink. Drought tolerant. Divide in spring.
‘Alba’ is white flowered. Not as robust as ‘Ozawa’. 12–15 in.
‘Ozawa’ sports heads of many reddish violet flowers. 12–20 in.
Allium tuberosum
• white
• late summer to early fall
• 12–30 in. × 12 in.
• sun, part shade
• Z4–8
Garlic chives, Chinese chives. Southeast Asia. Rhizomatous clumps of bulbs produce a mass of bluish green, flattened leaves, keeled at the base; these are edible and can serve as a substitute for garlic. In late summer, tall scapes topped with heads of small, starry, fragrant, white flowers appear that attract numerous pollinating insects. Deadhead to prevent widespread self-seeding, which may become a nuisance. Holds its own with white garden phlox ‘David’, spider plants, and panicle hydrangeas (Hydrangea paniculata) in white combinations in beds and borders. Seeds about too much for planting in rock gardens, but valuable in herb garden containers.
Allium tuberosum
Alstroemeriaceae
Peruvian lily, princess lily
These South American perennials are best known to the wider public as particularly long-lasting cut flowers. Indeed, to satisfy the appetite of the floral industry, millions of alstroemerias are raised in the fields and greenhouses of South America, Holland, and Israel, as well as California. They are often seen as symbols of friendship and devotion and are quite common in gift bouquets.
The genus Alstroemeria, named by Swedish botanist Carl Linnaeus for his friend, Baron Klaus von Alstroemer, includes some 60 species, a few of which are appropriate as garden flowers. Some, such as A. pygmaea, are highly ornamental, but are so demanding to grow that they are confined mainly in alpine greenhouses.
Alstroemerias arise from fleshy rhizome-like tuberous roots (invasive in some species) that generally form clumps up to 2 ft. or so across. Their stems are well clothed with narrow, mid-green leaves, grayish beneath and 3–5 in. in length; the petioles (leaf stalks) are twisted so that they invert the leaves. Showy, even gaudy flowers are tubular and held in loose, simple or compound umbels at the stem tips. Each flower is six tepaled (petals and sepals are not differentiated) and grows from 1.5–4 in. long. Attracts hummingbirds and butterflies.
Plant Peruvian lilies carefully, avoiding damage to the tuberous roots, in moisture-retentive, fertile, well-drained soil. Add organic matter at planting time and mulch with compost or well-rotted leaves annually to reduce water loss. The tuberous roots suffer if allowed to dry out. Evergreen in mild climates, alstroemerias go dormant in fall where winters are cold; protect clumps with evergreen boughs in winter. As alstroemerias brighten a floral arrangement, so too do they introduce more vivid hues into perennial and mixed borders. An obvious choice for cutting gardens, but a number of selections have been bred for planting in containers and at the front of borders. Tall selections look cheerful planted among evergreens such as rhododendrons, azaleas, and Japanese andromeda. Deadhead to extend bloom time.
Be alert for virus diseases and gray mold that mar the flowers and leaves. Slugs dine on young foliage and flowers, but deer and rabbits mostly ignore them. Those with sensitive skin may react to the sap of alstroemerias; protect hands with gloves when working with these plants.
Increase by division in spring or fall, or start seed in containers to avoid disturbing the tubers at transplanting time. Seed germinates readily.
Alstroemeria aurea
syn. A. aurantiaca
• orange
• summer
• 30–36 in. × 18 in.
• sun, part shade
• Z7–10
Peruvian lily. Chile. Clumps of running tuberous roots produce erect, well-foliaged stems. The tepals are bright orange, the upper pair freckled and splashed with red; exserted stamens are drooping.
‘Luna’ is clear yellow.
Alstroemeria huemulina
• orange
• summer to late summer
• 24 in. × 18 in.
• sun
• Z8–11
Peruvian lily. South America. Easy to grow, with clumps of non-running roots. Medium-size blooms are brown splashed, with brilliant deep orange tepals. First flush of bloom is repeated a few weeks later.
Alstroemeria psittacina
syn. A. pulchella
• red
• summer to fall
• 2–3 ft. × 3 ft.
• sun, part shade
• Z7–10
Parrot flower. Brazil. Clusters of exotic-looking brownish red flowers tipped with green. Mauve-spotted stems bear 3-in.-long, lance-shaped leaves. Roots spread widely and can become more than a nuisance. Best protected from intense afternoon sun. Very long-lasting as cut flowers.
‘Variegata’ has clean white–edged leaves. Red flowers are speckled with maroon and green. Summer dormant after bloom time. Z6–9.
Other Notable Cultivars
Alstroemerias are bred for the cut-flower trade but perfect for residential gardens. Most are well-behaved hybrids with amazing, sparkling flowers borne over a long season. This is a tiny sampling of what is available:
‘Casablanca’ has pink-flushed, white flowers flecked with maroon. 40 in. Z6–9.
‘Freedom’ is clump forming with reddish peach flowers blotched with cherry-sprinkled white on the upper petals. An introduction from Mark Bridgen’s Cornell breeding program. 30 in. Z5–8.
‘Glory of the Andes’ is a variegated selection derived from ‘Sweet Laura’. 24–30 in. Z6.
Inca Series, from Dutch breeder Könst, includes several superior introductions for compact, non-invasive growth and long bloom (early summer to fall). Inca Adore (‘Koadore’) has red flowers accented with a wide band of yellow with brown freckles. Inca Ice (‘Koice’) has whitish flowers, yellow at the throat and speckled with deep maroon dashes. Mostly 24 in. × 36 in. Z6–9.
Princess Lilies Series, bred by Van Zanten Plants in Holland, is superior for window boxes and planters, and at the front of cottage garden borders. Though frost sensitive, they are especially heat tolerant. Princess Oxana (‘Staprioxa’) is deep rose splotched with yellow and dashes of maroon. 10 in. Z7–8. Princess Ivana (‘Staprivane’) has 2-in.-wide, yellow-throated, cherry-red flowers. Mounding habit, great for containers and in the landscape. 12–15 in. Z8–11.
‘The Third Harmonic’ (Alstroemeria ‘Peach Harmony’ × A. aurea), introduced by George Hare, has large, orange flowers speckled with purple at the lip, and claret-flushed beneath. Tolerates warm, humid regions. 48 in. Z6–9.
Brassicaceae
madwort
Most madworts, including the summer-blooming Alyssum alpestre, silver madwort A. argenteum, and the pale yellow, spring-blooming A. wulfenianum, are candidates only for rock gardens, troughs, and between pavers. The larger species, however, can also fill spots at the front of sunny borders. Of some 150 species, few cope well with southern heat and humidity, although they may be grown in that region as colorful spring annuals.
Leaves of madworts are small, simple, and alternate, often grayish silver with hairs. Conspicuous, showy clusters of four-petaled, cross-shaped yellow or white flowers bloom in spring to early summer.
They are seldom bothered seriously by pests or diseases, but look out for aphids. Deer resistant.
Propagate by seed sown in spring or by softwood cuttings.
Alyssum montanum
syn. A. pedemontanum
• yellow
• mid- to late spring
• 8–12 in. × 12 in.
• sun
• Z2–7, HS
Mountain madwort. Northern Europe. Trailing mounds of silvery, evergreen foliage, above which rise clustered masses of bright mustard-yellow flowers.
‘Berggold’ (Mountain Gold) has a dense habit and abundant fragrant, bright lemon flowers. Combines well with other low spring bloomers, including rock cress and perennial candytuft.
Alyssum spinosum
syn. Ptilotrichum spinosum
• white
• late spring to early summer
• 6–12 in. × 18 in.
• sun
• Z6–9, HS
Spiny alyssum. Southern France, southeast Spain. Mounding with spatulate, evergreen, 2-in., silver-gray leaves and wiry stems clothed with prickly spines. Tiny, honey-scented, pink-tinged, white flowers crowd into terminal clusters. Appropriate for edging and rock gardens where drainage is good; drought tolerant. Rabbit resistant.
‘Roseum’ has white flowers tinged with lavender. Silvery foliage is interesting year-round. 8–12 in. tall.
Apocynaceae
bluestar
The underused bluestars are mostly native North American perennials that create floral displays in spring, often followed by amazing autumn foliage color.
The durable clumps are tough and easy to grow in ordinary garden soils that drain well; established plants tolerate short periods of drought. Clusters of starry flowers in various shades of pale blue top foliage-clad stems and provide nectar for early scavenging butterflies, especially mourning cloaks. After bloom time, slender seedpods remain on the plants.
Little maintenance is required: bluestars seldom need division and require staking only if grown in too much shade. If the plants begin to flop, encircle with wire rings or “pea sticks” (bushy, woody stems saved from shrub pruning); cut back by 6 in. after bloom time. Mostly disease free although susceptible to rust, bluestars are generally free of pests too, including deer and rabbits.
If used as cut flowers, sear the base of the stems with a flame to prevent the milky sap from bleeding and fouling the water. Some people report skin irritation from contact with the sap.
Propagate by division or softwood cuttings in spring. Species seeds germinate readily in spring or fall.
Amsonia ciliata
syn. A. angustifolia
• ice blue
• late spring
• 2–3 ft. high and wide
• sun, part shade
• Z5–9
Downy amsonia, fringed bluestar. Southeastern United States. Although it flourishes in the wild over a broad range, downy amsonia is not as popular for gardens as other species. However, it is an excellent plant, especially on sandy soils with pH above 7, amended with organic matter. Young growth is downy and silky soft. Showy clusters of flowers perch on erect but not very strong stems clothed with lanceolate, 1.5-in.-wide leaves. In sunny spots, fall foliage is brilliant yellow. If plants sprawl, prune gently into a rounded bush and support stems with pea sticks. Mass in native plant or wildlife gardens to attract butterflies and other insects. Astilbes and hardy geraniums are good border companions for spring; try goldenrods and blue leadwort for fall. Slow to establish.
‘Spring Sky’ has larger, longer-blooming flowers than the species. Fall color is yellow or bronze.
Amsonia hubrichtii
• steel blue
• late spring to early summer
• 3–4 ft. × 3 ft.
• sun, part shade
• Z5–9
Arkansas bluestar, Hubricht’s amsonia, narrow-leaved bluestar. Arkansas, Oklahoma. Not as stiffly upright as other species, this easy-care Arkansan native has smooth, thread-like leaves that present unusual textural beauty. Provide acid soil and a sunny site; in too much shade, plants will open up and sprawl. The showy powder-blue, 0.5-in., starry flowers cluster at the tops of the stems, where they attract butterflies; needle-like fruits follow. Cut back by 6–10 in. after bloom time to groom the plants into a neat mound of feathery foliage; the fruits will be lost in this process, but fall color will be more dramatic. Plants grown in full sun produce the best fall color, an arresting banana yellow and orange. Arkansas bluestar is perfect for native, wild, and wildlife gardens; in flower borders, combine with peonies, Oriental poppies, and late-blooming perennials, or provide a dark-leaved shrub, such as ninebark (Physocarpus) or Weigela Wine and Roses (‘Alexandra’), as a background. The brilliant fall foliage is eye-popping against tall sedums ‘Matrona’ and ‘Autumn Joy’. Slow to establish. Named the Perennial Plant of the Year for 2011 by the Perennial Plant Association.
Amsonia hubrichtii
Autumn foliage of Amsonia hubrichtii
Amsonia montana
syn. A. tabernaemontana ‘Montana’
• light blue
• spring
• 12–24 in. × 9–12 in.
• sun, part shade
• Z3–9
Dwarf bluestar. Massachussetts to Missouri. Now considered by some authorities to be a species in its own right, dwarf bluestar differs from Amsonia tabernaemontana in producing dense clusters of somewhat deeper blue flowers earlier in spring on more compact plants. Drought tolerant once established. In sun, the willowy leaves turn gold in fall.
‘Short Stack’ is a 12-in.-tall dwarf selection. Z5–9.
Amsonia orientalis
syn. Rhazya orientalis
• lavender-blue
• spring
• 18 in. high and wide
• sun, part shade
• Z6–9
Bluestar. Greece, Turkey. A change in taxonomy has brought this European native into the Amsonia genus. Popular in the UK and Europe, this plant is quite similar to A. tabernaemontana, but with a more refined look. The flowers are larger and a stronger blue, best seen when plants are grown in part shade. Keep soil moist, especially in sunny places.
Amsonia tabernaemontana
syn. Tabernaemontana amsonia
• pale blue
• mid- to late spring
• 2–3 ft. high and wide
• sun, part shade
• Z3–9
Blue starflower, blue dogbane, eastern bluestar. Eastern and central United States. Upright with somewhat stiff stems, blue starflower is clothed with smooth, willow-like leaves. In sun, these turn brilliant yellow come fall, though its color is not as spectacular as that of Arkansas bluestar. Pale blue, starry flowers cluster at the ends of the stems; spindle-like fruiting pods follow. This tough plant tolerates less than ideal conditions, but prefers a moist, well-drained soil. Spectacular massed in rough meadows or native plant gardens as well as in butterfly gardens where it provides food for coral hairstreak caterpillars. In beds and borders or among shrubs, group several plants together. An excellent cut flower, sear the base of the stems before conditioning them to prevent sap bleed. Lovely in front of shrubby yellow potentillas or dark-leaved ninebark.
var. salicifolia (syn. Amsonia salicifolia), woodland or willow-leaved bluestar, has very slender leaves. 2–2.5 ft.
Other Notable Cultivars
‘Blue Ice’ is a hybrid selection from Amsonia tabernaemontana, possibly with A. montana or A. orientalis. Extremely long blooming, with terminal clusters of intense deep lavender flowers, good for cutting. Tolerates part shade, but in sun foliage turns vivid yellow and orange in fall. Provide consistently moist, humus-rich soil; drought tolerant and adapts to hot, humid summers. Compact, ideal for small gardens. 15 in. × 24 in. Z5–9.
‘Seaford Skies’ (A. hubrichtii × A. tabernaemontana) displays hybrid vigor. Pyramidal clusters of star-like, sky-blue flowers from mid- to late spring. Vibrant yellow fall color. Bred by noted garden writer Pam Harper. 3 ft. × 5 ft. Z5–9.
Asteraceae
Mt. Atlas daisy
Just one species in this genus of about 15 species is of interest to gardeners, especially those that have shallow, poor, but well-drained soil.
Anacyclus pyrethrum var. depressus
syn. A. depressus
• white
• early to midsummer
• 1–3 in. × 15 in.
• sun
• Z5–8, HS
Mt. Atlas daisy, mat daisy. Mountains of Morocco. Mat-like rosettes of finely dissected, crinkly, gray-green leaves, from the center of which sprawl prostrate and ascending flower stems. These bear red flower buds that on sunny days open to single, yellow-centered, 1-in., white daisies borne above the foliage. The flowers close at night and during cloudy weather, revealing a charming red reverse. Provide very well-drained, poor soil for best results. Needs little water; will succumb to root rot if kept too wet. Apply a gravel mulch to improve water runoff from the foliage cushion. Easily grown as a groundcover for dry places, and a fine rock garden, trough, and crevice garden plant; effective along the edges of gravel paths where Mt. Atlas daisy will seed itself. Partners well with mossy saxifrages and low sedums. Best in cooler climates; the combination of high heat and humidity is likely to be fatal. Resistant to deer. Easily propagated by seed sown in spring.
Anacyclus pyrethrum var. depressus
‘Garden Gnome’ is reputedly more compact than the species.
‘Silberkissen’ (‘Silver Kisses’). Silvery feathery leaves on compact, 3-in. plants. Flowers 1–2 in. across. Perfect for troughs.
Asteraceae
pearly everlasting
The clustered white flowers of this genus are long blooming and even longer lasting; when cut and dried they are a staple of dried flower arrangements. In the garden, their white blossoms and gray-green foliage serve as cooling counterpoints to other, hotter-colored perennials. They add a subtle floral note to dry meadows or prairies, native plantings, and wildflower gardens; butterflies love them. The genus includes 110 or so species that grow wild in various types of habitats throughout the Northern Hemisphere. The diversity of their origins makes this a versatile group of perennials that flourishes in both moist and dry conditions. In general, pearly everlastings are trouble free, and require very little maintenance.
Propagate by seed started indoors or direct sown in spring, or divide in spring or fall.
Anaphalis margaritacea
• white
• mid- to late summer
• 1–3 ft. × 1–2 ft.
• sun, part shade
• Z3–8
Western pearly everlasting. Northern North America, northern and central Europe, northeast Asia. In the wild, this species grows on dry, sandy, or gravelly soils, but in gardens it thrives on any average, well-drained soil; tolerant of nutrient-poor soils and drought. The handsome foliage—narrow, woolly, and silvery gray—complements the flattened clusters (corymbs) of tiny, globular, yellow-centered, white flowers at stem tips. The stoloniferous roots may spread aggressively on favorable sites. Excellent for xeriscapes or where water is limited.
Anaphalis triplinervis
• white
• early summer to early fall
• 18–24 in. × 9–18 in.
• sun, part shade
• Z3–9
Pearly everlasting. Himalayas from Afghanistan to southwestern China. Less drought tolerant than Anaphalis margaritacea. Provide humus-rich soil that is well drained but consistently moist. Borne on zigzag stems, the very narrow, elliptic-obovate leaves to 5 in. long are gray on top and downy white beneath; they will degenerate rapidly if irrigation is neglected during dry spells. Individual flowerheads, 0.75 in. or so across, are surrounded by collars of papery white bracts; collectively, the flowerheads are borne in dense, domed corymbs. A good choice for cottage gardens and wild gardens.
‘Summer Snow’ (‘Sommerschnee’) has flowerheads of a purer white than the species, and the yellow centers are less visible.
Boraginaceae
alkanet
Usually short lived, perennial alkanets provide true-blue flowers, a rare color among garden plants whose “blue” flowers are more typically lavender- or purple-blue. Alkanet stems and leaves are coarsely hairy and the forget-me-not-like flowers are arranged at the tip of the stems, coiled in a bud like the tail of a scorpion (scorpioid). Stem leaves are alternate and clasping.
With their awkward, rather lax habit, alkanets are not the most elegant of plants but combine well with peonies, irises, and others in the midsection of flowerbeds and borders where their ungainliness is not obvious. They attract butterflies and bees, but are seldom browsed by deer or rabbits. Cutworms and vine weevil larvae may attack the roots.
Best propagated from pencil-thick root cuttings in late winter, or basal cuttings in spring. Sow seed in containers in spring.
Anchusa azurea
syn. A. italica
• blue
• early summer
• 3–5 ft. × 2 ft.
• sun
• Z3–8, HS
Italian alkanet, Italian bugloss. Mediterranean region. Italian alkanet thrives in rather dry, poor soils typical of its native region. The combination of southern heat and humidity is not to their liking, but plants thrive and are long lived in the dry heat of southern California. Winter wet causes root rot. In the garden, excess water or fertilizer promotes undesirable rank, floppy growth. Branching flower stems rise above clumps of mostly basal 4- to 12-in.-long, coarsely bristly leaves, and may need staking—best done with pea sticks or brush. The tubular and flaring, 0.5-in. flowers are abundant and provide glorious gentian-blue color for several weeks. Cut back to the basal leaves after blooming. The species is grown infrequently, but several superior cultivars are available. All make eye-catching combinations with tickseeds, blanket flowers, Shasta daisies, and silver-leaved artemisias, and in front of variegated shrubs.
‘Dropmore’ is a tried-and-true cultivar with deep blue flowers in mid- to late summer. At 4–5 ft. tall, it usually needs staking.
Anchusa azurea ‘Dropmore’
‘Feltham Pride’, sometimes listed as Feltham Pride strain, has medium blue flowers on multi-branched, 30- to 36-in.-tall stems.
‘Little John’ is dwarf, perfect for smaller gardens. The bright steel-blue flowers bloom from late spring into summer. Late daffodils make colorful companions. 16–20 in.
‘Loddon Royalist’ produces 0.75-in., gentian-blue flowers in late spring and early summer. 3 ft. tall.
Ranunculaceae
windflower
When the breeze sets their long-stemmed clusters of silken-petaled flowers dancing, anemones truly earn their common name of windflower. On a more practical level, the many species of this hardy and vigorous genus offer such a variety of blooming seasons that one could furnish a garden with flowers throughout the growing year with anemones alone. Wood anemones (Anemone nemorosa), for example, supply some of the first flowers of spring, while the fall-blooming Japanese anemone (A. ×hybrida) with its graceful, informal blossoms, provides the perfect counterpoint and companion to autumn’s bombastic chrysanthemums.
Anemone blooms consist of single, or occasionally double, circles of petal-like tepals surrounding a central knot or boss of thread-like, usually golden stamens. The overall effect ranges from daisy-like in some species to looser, almost poppy-like flowers in others. Typically, anemone leaves emerge from the base of the plant on long stems. They may be divided palmately like fingers, lobed and toothed, or sometimes palmately compound; the lush but neat mounds of leaves furnish a handsome complement to other, showier foliage plants such as hostas, grasses, and ferns.
Though best adapted to partial shade, anemones tolerate full sun in cool climates, and flourish on most well-drained soils other than heavy clays. The spring- and summer-blooming species are tuberous rooted or rhizomatous, and these roots should be planted in fall like spring bulbs. The fall bloomers are more commonly fibrous rooted, best planted in spring or fall along with other perennials.
Include anemones in beds and borders, though they are also appropriate in woodland gardens. Spring-blooming species partner well with lungworts, woodland phlox, and foamflowers; the fall bloomers do well with Japanese toad lilies, Allium thunbergii ‘Ozawa’, and asters. The tuberous-rooted species (including Anemone blanda) can be forced in containers like spring bulbs. Seldom browsed by deer but need protection from slugs; anemones provide long-lasting cut flowers.
Propagate and reinvigorate named cultivars by division every two to three years, ideally in early spring; species may be started from seed sown as soon as it ripens.
Anemone blanda
• blue, pink, red, white
• early spring
• 6–9 in. × 4–6 in.
• sun, part shade
• Z5–8
Grecian windflower. Southeastern Europe and Middle East. This tuberous-rooted species naturalizes readily in well-drained soils. It spreads by seed or by root to form expansive mats of foliage and, in season, brightly colored, daisy-like flowers. Especially attractive under spring-flowering trees. Soak tubers overnight before planting. Prone to a variety of fungal diseases, though rarely seriously affected. Slugs and snails may be a problem. Deer damage is rare.
‘Blue Shades’ produces blooms in a range of blues.
‘Charmer’ is deep lilac accented with a white ring around the stamens.
‘Radar’ has magenta-pink flowers with contrasting white eyes.
‘Violet Star’ has white-eyed, amethyst flowers and yellow stamens.
‘White Splendour’ has pure white, daisy-like flowers accented with yellow stamens.
Anemone coronaria
• blue, red, white
• midspring to early summer
• 9–18 in. × 6–9 in.
• sun, part shade
• Z7–10
Poppy anemone. Native throughout the Mediterranean basin and considered by some to be the Biblical “lilies of the field.” Tuberous roots bear solitary, showy, poppy-like, single flowers to a diameter of 2.5 in. with six to eight colorful tepals and black centers, borne on 10- to 12-in. stems. May be grown in containers; popular and long-lasting cut flower.
De Caen Hybrids is an heirloom strain that has poppy-like, single flowers of scarlet, violet-blue, white, or mauve.
‘Mr. Fokker’ bears single, violet-blue flowers.
St. Brigid Hybrids is another heirloom strain with semi-double or double, dahlia-like flowers of scarlet, violet-blue, white, and mauve.
Anemone hupehensis
• pink
• mid- to late summer
• 18–24 in. × 12–18 in.
• sun, part shade
• Z4–8
Japanese anemone, Japanese thimbleweed. Actually native to central China, this misnamed perennial bears 2- to 3-in.-wide, slightly cupped flowers; typically these have five rose-pink tepals surrounding a prominent central ring of yellow stamens. Prefers a moderately fertile soil; ideal for partially shaded woodland gardens or borders. Seeds about and may become aggressive in ideal conditions. No serious pests.
‘Praecox’ is an exceptionally robust cultivar, blooming early in midsummer. To 50 in. tall.
var. japonica ‘Bressingham Glow’ (syn. Anemone ‘Bressingham Glow’) bears deep pink, semi-double or double flowers with a silvery sheen.
‘Pretty Lady Diana’ belongs to a line of dwarf cultivars. Masses of single, 2-in.-wide, pink flowers. ‘Pretty Lady Emily’ has semi-double, silver-pink flowers. Ideal in containers. 16 in. × 24 in. Z5–9.
Anemone ×hybrida
• white, pink
• late summer to fall
• 24–48 in. × 12–18 in.
• sun, part shade
• Z4–8
Japanese anemone. A collection of garden hybrids similar to Anemone hupehensis; some authorities treat these as a subdivision of that species.
‘Andrea Atkinson’ has white, single or semi-double flowers, to 3–5 ft. ‘Whirlwind’ is similar. 2–4 ft.
Anemone ×hybrida ‘Whirlwind’
‘Honorine Jobert’ flowers are pure white and single. The benchmark for white-flowered introductions.
‘Konigin Charlotte’ (‘Queen Charlotte’) is vigorous; 4-in.-wide, semi-double, pink flowers with purple backs.
‘Pamina’ is double with deep rosy tepals.
‘Prinz Heinrich’ (‘Prince Henry’) resembles ‘Bressingham Glow’ but spreads more quickly.
‘September Charm’ is silvery pale purple, single.
Anemone nemorosa
• pink, purple, white
• late winter to midspring
• 6–12 in. × 6–9 in.
• sun, part shade
• Z5–8
Wood anemone. Northern Europe to western Asia. Naturalizes well in moist woodlands, expanding by rhizomes into large colonies; can become a pest if allowed to spread unchecked. Flowers about 1 in. across with six to eight tepals. Foliage is similar to that of Anemone blanda; it dies back right after bloom.
‘Allenii’ has large, lavender-blue flowers.
‘Bowles’ Purple’ has purple flowers.
‘Bracteata Pleniflora’ is semi-double with green-tipped, double, white flowers.
‘Vestal’ is double, with pompon-like white flowers.
A. ×lipsiensis ‘Pallida’ (A. nemorosa × A. ranunculoide), has pale yellow flowers.
Anemone patens
syn. Pulsatilla patens
• blue-violet
• early spring
• 3–12 in. × 3–6 in.
• sun
• Z3–7
Eastern Pasque flower. Northern Europe, Russia, North America (Alaska south to Washington, New Mexico, Texas, and Illinois). State flower of North Dakota. One of the first spring wildflowers of the northern Great Plains, with flowers opening while foliage is still emerging, often amid patches of snow. Basal foliage deeply divided, fern-like, and covered with silvery hairs. Flowers, usually blue-violet but occasionally white or yellow, are bell shaped and open, borne on 4- to 5-in.-tall stems that stretch to 8–12 in. as blossoms mature. Followed by plume-like, ornamental seedheads. Best in gritty, well-drained, dry to moderately moist soils in cool climates; tolerates light shade. Somewhat difficult from seed. No serious pests or diseases, welcome harbinger of spring in rock gardens, prairie plantings, and border fronts.
Anemone sylvestris
• white
• spring
• 12–18 in. × 9–12 in.
• part shade, shade
• Z4–8
Snowdrop anemone. Central and eastern Europe. A reliable and undemanding plant that prefers sandy, organic-rich soils. Naturalizes in hospitable sites and can be aggressive on loose soils; spreads less in clay. Nodding, fragrant, cupped, five-tepaled, white flowers with yellow anthers. The 1.5- to 2-in.-wide flowers are borne on 18-in. stems above medium green, deeply lobed foliage. White, woolly seedheads follow the flowers. Excellent for woodland gardens or meadows.
Anemone tomentosa
syn. A. vitifolia
• pale pink
• late summer to fall
• 2–3 ft. × 15–18 in.
• sun, part shade
• Z4–8
Grape-leaf anemone. This native of northern China prefers a moist site, but rots on persistently wet soils. A source of spectacular late-season color, Anemone tomentosa is robust—indeed, it is most often available as the cultivar ‘Robustissima’. It forms dense mounds of deep green, attractively cut foliage, above which rise branching stems topped with clusters of cupped, pinkish mauve flowers. Naturalizes readily, but it can be aggressive, overwhelming neighbors in the border. Impressive among shrubs.
Anemone vulgaris
syn. Pulsatilla vulgaris
• purple, white
• early spring
• 9–12 in. high and wide
• sun, part shade
• Z4–8
Pasque flower. Northern Europe. Flowers are five sepaled, goblet like, and solitary, 2–4 in. across. They range in color from blue to reddish purple, with a central knot of golden stamens; blooms appear before leaves, borne on stout stems. Pasque flower forms low clumps of silky, fern-like, deeply cut basal leaves, 3–6 in. long and gray-green. Flowers give way to showy, feathery seedheads. Prefers rich, humusy soil but tolerates most average, well-drained, moderately moist ones. No serious pests or diseases. Provides early color and texture for rock gardens and border fronts.
‘Rote Glocke’ (‘Red Bells’) has bright crimson flowers.
Anemone vulgaris
Ranunculaceae
rue anemone
This is another single-species genus, and not to be missed. A charming native woodlander that sparkles in late winter sun.
Anemonella thalictroides
syn. Syndesmon thalictroides, Thalictrum thalictroides
• white
• spring to early summer
• 4–6 in. × 6–12 in.
• part shade
• Z4–8
Rue anemone. Eastern states, west to Oklahoma and Texas. With foliage that resembles that of meadow rue, rue anemones are among the most charming of our spring ephemerals. Growing from underground tubers, delicate slender stems carry blue-green, thrice-divided (ternate) leaves, the terminal leaflet scallop toothed. Grouped in clusters, the 0.5-in.-wide, sparkling white or pale pink flowers each have up to ten petal-like sepals, surrounding a central knob or boss of stamens; true petals are absent. Small, ribbed fruits, similar to those of related buttercups, follow. Easy to grow in average, well-drained soil amended with humus. Rue anemones do not tolerate drought, and become dormant as summer heat settles in after bloom. Plants bulk up slowly, but are worth the wait. Suitable to line woodland paths, among shrubs, in shaded rock gardens and native plant gardens, or even in troughs or containers with other shade lovers. Any of the cultivars makes an attractive partner for diminutive anemones, primroses, or green ’n golds. They are seldom browsed by deer; pest and disease free.
Propagate by seed sown in fall and overwintered outdoors, or by division. Sensitive-skinned gardeners may have an adverse reaction to the sap, so wear gloves if dividing the clumps.
‘Cameo’ has double, rose-pink to white flowers.
‘Eco-Pink’, selected by Don Jacobs, from Decatur, GA, is a single-flowered pink.
‘Just Precious’ (‘Jade Feather’, ‘Green Hurricane’, ‘Green Dragon’). This novelty, probably only for collectors, has unique double, green flowers.
‘Schoaff’s Double Pink’ (‘Schoaf’s Pink’, ‘Schoaf’s Double Pink’) is widely grown. It is similar to ‘Cameo’, but with only pink flowers.
Ranunculaceae
false anemone
A single species is all this genus has to offer, but it is a prize. A Japanese woodland native, false anemone is similar to but smaller and daintier than a Japanese anemone. A natural for woodland gardens and shady borders, false anemone mixes easily with other shade lovers such as ferns, hostas, hellebores, and lungworts. Pests and diseases are seldom a problem. Resistant to deer.
Propagate by division in early spring or fall, or sow seed as soon as it ripens either in a nursery bed or in containers overwintered outside—a period of chilling is required to break dormancy.
Anemonopsis macrophylla
• lavender-pink
• midsummer to early fall
• 2–3 ft. × 1.5 ft.
• part shade, shade
• Z5–8
False anemone. Japan. Airy fern-like foliage provides an attractive backdrop for exquisite 1-in., nodding, bowl-shaped, waxy blossoms. Plant in acid, well-drained soil in a sheltered spot away from dehydrating summer winds. Provide moist soil conditions during the growing season; it will not tolerate wet feet during winter dormancy. Tolerates full sun only in moist, cool regions such as the Pacific Northwest.
Apiaceae
angelica
Angelicas are familiar as dramatic features of medicinal herb gardens, but their stately architectural presence makes them an asset in ornamental plantings as well. The strong stems are hollow; each petiole (leaf stem) sheaths the stem at the node. The leaves are twice divided into three. Provide rich soil amended with plenty of humus to retain soil moisture. Sometimes attacked by aphids. Ignored by deer.
To propagate, sow seeds as soon as they are ripe, leaving them uncovered, as light is required for germination. Transplant seedlings promptly to avoid trauma to their sensitive root systems.
Angelica archangelica
• white
• early summer
• 5–7 ft. × 4 ft.
• sun, part shade
• Z4–8
Archangel, wild parsnip. Native to Scandinavia and Greenland. Strongly vertical and statuesque, archangel is a short-lived perennial or biennial. Its divided leaves may reach 2 ft. in length, the leaflets toothed along the edges. Countless, small, greenish white flowers are held in large, domed umbels, sometimes 8 to 10 in. across; these make intriguing additions to floral arrangements. Deadheading before seed set may promote a longer lifespan for individual specimens. However, as this species comes so easily from seed, it is prudent to keep a supply of young plants that can serve as understudies. Archangel makes an excellent focal point in damp or even wet places, or at the back of large borders. Partner in herb and vegetable gardens with rhubarb for dramatic impact; ornamental rhubarb, Rheum palmatum ‘Atrosanguineum’, makes a stunning companion at the back of ornamental borders. Dark-leaved cultivars of weigela, smokebush, and ninebark, and variegated red-stemmed dogwoods are reliably memorable companions in shrub collections.
Young leaves and stems of archangel are edible and were formerly used as natural sweeteners; bright green, candied angelica tastes of anise and can be used to decorate cakes and cookies.
• purple
• late summer to early fall
• 3–6 ft. × 4 ft.
• sun, part shade
• Z4–9
Purple parsnip, Korean angelica. Native to damp woodlands of Japan, northern China, and Korea. This vigorous plant is a good conversation piece in any garden, especially when it blooms in its second year. Light green leaves that may reach 12 in. or more in length, borne on purplish stems; where leaves meet stems, the nodes are covered with inflated burgundy sheaths. Purple clusters of buds open to domed, 8-in.-wide heads of deep plum flowers. Best in full sun in cool regions, but shield from intense sun elsewhere. Partner with dark-leaved shrubs or perennials, or create an eye-catching vignette with Joe-Pye weed, or tall willow-leaf sunflowers. Self-seeds but not reliably. Assist this process by putting a paper bag over the ripening seedhead to collect the seeds as they dry; sow fresh seed outdoors in fall, or chill and sow indoors in an unheated structure.
Angelica gigas
Asteraceae
pussy-toes, cat’s-ears
Don’t let the common name mislead you—these small, furry plants may have a cuddly appeal, but they are tough, resilient groundcovers, thriving on dry and poor soils in sun-drenched, drought-prone locations. They tend to be enthusiastic spreaders; select one of the many native North American species to avoid turning your garden into a beachhead for an exotic invasive.
Though there is variation from species to species (there are 45 of them), in general pussy-toes share silver, furry, fine-textured foliage and a mat-forming pattern of growth. The everlasting flowers, borne in dense heads on furry, upright stems, do suggest the upthrust foot of some botanical feline; white or pink, the flowerheads individually are insignificant but massed they have a certain charm. The generic name, Antennaria, refers to thread-like stamens that sometimes protrude from the flowers, resembling the antennae of insects.
As a group, pussy-toes attract insect pollinators. Some native species play a crucial role in the life cycle of some native moths, including white-spotted midget moth, whose larvae feed exclusively on these plants. Not a favorite of deer.
Though they adapt to a wide range of soils, good drainage is essential, especially in winter. They compete most effectively in dry, sunny situations. In rock gardens they are valuable as groundcovers, especially interplanted with small bulbs and dwarf conifers, and they flourish when tucked into the joints of a flagstone pavement or path. Here, they may complement other herbs, such as creeping thymes, with elegance. They will tolerate heat, but not humidity, and are therefore unsuitable for southeastern US gardens.
Propagate by dividing established clumps in early spring, or sow seed in fall for spring germination.
Antennaria dioica
• white, pink
• late spring to early summer
• 2–5 in. × 18 in.
• sun
• Z5–9, HS
Pussy-toes. North America, Europe, northern Asia. Handsome, fine-textured foliage, excellent for xeriscapes as well as dry spots in ordinary landscapes.
‘Nyewoods’ is compact with deep rosy pink flowers.
‘Rubra’ has deep pink flowers.
Antennaria dioica
Antennaria rosea
• pink, white
• early to late spring
• 4–6 in. × 6–9 in.
• sun
• Z3–8, HS
Rosy pussy-toes. Open woods and meadows of western North America. Forms dense mats of fine, velvety, silver-green foliage, with light pink or white flowerheads. Drought tolerant once established. Reseeds and spreads readily in hospitable environments.
Asteraceae
chamomile
Summer-long bloom and aromatic, divided leaves make this genus valuable for sunny, well-drained borders and rock gardens. Average or even poor soil is fine; overly rich soil produces soft, disease-prone growth. The white or yellow daisy flowers are carried atop long stems; they are often fragrant and make good cut flowers, as well as attracting butterflies to the garden. Chamomile does best in cooler climates and may melt in the heat and humidity of southern gardens. Seldom browsed by deer, but protect young plants from slugs.
Propagate by seed sown in spring, by division in spring, or by rooting basal cuttings in late spring to early summer.
Anthemis ×hybrida
• yellow, white
• summer
• 24–30 in. × 24 in.
• sun
• Z3–8
Hybrid chamomile. Of hybrid origin. Several of the named cultivars in this genus are probably hybrids of Anthemis tinctoria and either A. sancti-johannis or A. punctata subsp. cupiana, but may still be listed under A. tinctoria in some catalogs. They are fine long-blooming border plants that mix well with speedwells, yarrows, phlox, and lupines. Keep soil moist; stake if necessary. Excellent cut flowers.
‘E. C. Buxton’ has lemon-centered, cream daisies.
‘Grallagh Gold’ produces bright golden flowerheads on 24-in. stems.
‘Kelwayi’ has bright yellow flowers.
‘Moonlight’ is pale yellow with deeper yellow centers. Flowers may bleach out in full sun.
‘Susanna Mitchell’ has yellow-centered, creamy-white daisies and silver-green, feathery leaves. It is drought tolerant and appropriate for xeriscapes. Combine with blue bellflowers or salvias. 18–24 in. tall.
Anthemis marshalliana
syn. A. biebersteiniana, A. rudolphiana
• yellow
• late spring to early fall
• 10–18 in. × 12–24 in.
• sun
• Z5–8, HS
Marshall’s chamomile. Caucasus. Bright yellow daisy flowers, 1–2 in. across, rise above low mats of silky, silver foliage. Routine deadheading extends the bloom period. Not recommended for hot, humid gardens.
Anthemis punctata subsp. cupiana
syn. A. cupiana
• white
• early summer
• 8–12 in. × 36 in.
• sun
• Z5–8, HS
Sicilian chamomile. Italy. Beautiful lacy, gray-green leaves spread out in delicate mats of foliage. In early summer, stems are topped with solitary, yellow-eyed, white daisy flowers, 1–2 in. across. Superb in rock gardens or at the front of the border, perhaps with Dalmatian bellflower and woolly speedwell. Does poorly in heat and humidity.
Anthemis sancti-johannis
• orange
• summer
• 24–36 in. × 24 in.
• sun
• Z3–8
Golden marguerite, St. John’s chamomile. Southwestern Bulgaria. This bushy clumper has ferny, grayish, 2-in. leaves covered with soft hairs. Its 2-in.-wide, very short-rayed, bright orange daisy flowers are deep yellow in the center. Excellent, long-lasting cut flowers. Keep soil moist, and deadhead routinely to extend bloom time. May need staking. Attracts bees and butterflies. Self-seeds gently, or collect seed and direct sow in fall.
Anthemis tinctoria
• yellow
• summer to fall
• 24–36 in. × 24 in.
• sun
• Z3–7, HS
Golden marguerite. Europe, Caucasus, Turkey. A clumping perennial with green, ferny leaves, gray with soft hairs beneath. Yellow to cream daisies, 1 in. or more across, bloom atop branched stems for several weeks. Do not allow to completely dry out in hot weather; stake if necessary. Tends to melt in the heat and humidity of southern summers. This species is a parent of several excellent hybrids.
Anthemis tinctoria ‘Kelwayi’
Asparagaceae
St. Bernard’s lily
Though not particularly showy in themselves, the two species of St. Bernard’s lily commonly cultivated as garden perennials have the valuable ability to serve as foils for other, more visually assertive plants. Charming and easy to grow, they deserve wider use in American gardens. Both of the garden species form tussocks of grass-like leaves and bear white, six-tepaled flowers on tall, slender stalks. The two are also alike in their adaptability: if given a rich, well-drained soil and a sunny site, they’ll thrive in southern New England and the Pacific Northwest, as well as in the humidity of a Florida summer and the drier heat of southern California.
Wherever you grow them, they make a dramatic contrast when set against dark-foliaged shrubs such as ‘Black Lace’ or ‘Black Beauty’ elderberries, and the hybrid ninebark ‘Summer Wine’. The grassy foliage of St. Bernard’s lilies also integrates easily with plantings of compact ornamental grasses. In combinations of this kind, the flowers serve as a delightful surprise. Try a combination with spike speedwells and hardy geraniums, or peonies.
Propagate by seed direct sown in fall or started indoors in early spring—seedling anthericums take a couple of years to reach blooming size. Established clumps may be divided in spring. Guard against slugs and snails.
Anthericum liliago
• white
• late spring to early summer
• 24–36 in. × 12–16 in.
• sun
• Z5–9
St. Bernard’s lily, grass lily. Dry pastures, open woods, and stony soils in Europe and Turkey. Rhizomatous-rooted clumps bear airy spikes of fragrant, 1-in.-long, white flowers that open sequentially from the bottom of the spike to the top, prolonging the period of bloom. This unbranched species is particularly attractive when naturalized in a meadow with grassland bulbs such as Narcissus, Camassia, and Allium. Good for cutting.
‘Major’ (syn. Anthericum algeriense) has larger flowers than the species, snowy white on 2.5-ft. stems. Midsummer bloom.
Anthericum ramosum
• white
• early to midsummer
• 16–32 in. × 12 in.
• sun, part shade
• Z5–9
St. Bernard’s lily. Western Europe to central Asia. Forms a trim, compact clump of grassy leaves, 20 in. long and 0.2 in. wide. Beginning in midsummer, erect, branched stems emerge to bear clouds of 1-in., starry, white flowers, each with a yellow ovary and sporting yellow anthers; bloom is repeated periodically throughout the summer.
Ranunculaceae
columbine
Both the scientific and common names celebrate this plant’s intriguing flower structure. Aquilegia derives from the Latin for “eagle,” and refers to the five long, hollow spurs sweeping back from the flower’s face, supposedly resembling the talons of a bird of prey; columbine (Latin for “dove”) offers a gentler vision—turn the flower over and look for the resemblance to five doves perched around a fountain. In addition to the flowers, aquilegias offer daintily divided or lobed, rich green or blue-green foliage.
Aquilegia ‘Origami Red-and-White’
Easy to grow, columbines thrive in most soils as long as they drain well. To promote the best growth and bloom, water regularly but avoid soaking; overwatering is generally fatal. Full sun is fine in cooler, northern regions; morning sun with afternoon shade is preferable in warmer ones.
The most common pest is leaf miner, which disfigures the foliage by burrowing beneath the leaf surface, marking it with pale, winding tracks; cut back to the ground and destroy foliage of infested plants immediately after bloom time. This promotes healthy new growth. The seeds and roots of columbines are toxic, and should not be ingested. Resistant to deer and rabbits, but attractive to hummingbirds and butterflies.
Plant larger-flowered species and hybrids in borders with spring bulbs and perennials: perennial flax, dame’s rocket, and spurges for example. Less showy types adapt well to rock gardens and at woodland edges. Well suited to cottage gardens and excellent in containers and as cut flowers.
Easily started from seed; propagate named cultivars by dividing mature clumps carefully; columbines resent root disturbance and are slow to recover from such treatment.
syn. A. montana
• blue
• late spring
• 1–2 ft. × 6–12 in.
• sun, part shade
• Z4–8
Alpine columbine. European Alps. Flowers are cobalt blue, 2–3 in. across. Well-drained soil is essential; prefers partial shade in warmer, sunnier regions. Reseeds freely in hospitable locations.
var. alba bears white flowers on slightly shorter plants.
Aquilegia caerulea
• blue, white
• spring to early summer
• 8–24 in. × 18–24 in.
• sun, part shade
• Z3–8, HS
Rocky Mountain columbine. Rocky Mountain states. Large flowers to 3 in. across, white and pale to cerulean blue. Provide protection from afternoon sun in the warmer part of its range. Self-seeds in hospitable locations.
‘Florida’ has bicolored flowers of pale and golden yellow.
‘Georgia’ has extra-large, red flowers with white corollas.
‘Kristall’ is pure white.
‘Red Hobbit’ is dwarf with carmine flowers with white corollas. 12–15 in.
Aquilegia canadensis
• pink, red-yellow
• mid- to late spring
• 2–3 ft. × 1–1.5 ft.
• sun, part shade
• Z3–8
Canadian columbine. Rocky woods, slopes, and open areas throughout North America, east of the Rockies. Bright red flowers with yellow corollas dance in the slightest breeze. Adapts to a wide range of soils, including dry ones. Attractive to hummingbirds, well suited to wildlife gardens as well as native plant collections. Tolerates drought, deer, and rabbits. Self-seeds and naturalizes in hospitable locations. Reportedly resistant to leaf miners.
‘Corbett’ has pale yellow flowers on 8- to 10-in.-tall plants. May lack vigor.
Aquilegia canadensis ‘Corbett’
‘Little Lanterns’ is a dwarf that bears brilliant red flowers with yellow corollas. 8–10 in.
Aquilegia chrysantha
• yellow
• late spring to early summer
• 1–3 ft. × 1–3 ft.
• part shade, shade
• Z3–8
Golden columbine. Southwestern North America. Delicate flowers have gently curving spurs to 3 in. long. Fast growing and successful on a wide range of well-drained soils; keep well watered in full sun in cool climates; prefers partial shade elsewhere. Self-seeds in hospitable locations. Rust and powdery mildew may attack in dry summers; be alert for fungal leaf spots and the occasional southern blight.
‘Yellow Queen’ bears especially bright yellow-and-gold flowers.
Aquilegia ecalcarata
syn. Semiaquilegia ecalcarata
• red, purple
• spring
• 15–18 in. × 12 in.
• sun, part shade
• Z4–7
Spurless columbine. Japan, China, Korea. This short-lived perennial has ternate, 10- to 12-in. basal leaves on long petioles. The leaflets are sometimes further divided. Starry burgundy to purple flowers nod in loose clusters atop branched stems; in this species, the floral spurs of other aquilegias are replaced by small pouches at the base of the flowers. Semiaquilegia adoxoides is similar but has pale pink flowers.
Aquilegia flabellata
syn. A. atkinensis
• purple, white
• spring to early summer
• 1–3 ft. × 0.5–1 ft.
• sun, part shade
• Z4–8
Fan columbine. Japan and Korea. Flowers are bicolored, bluish purple with white tips and centers. Self-seeds in hospitable locations.
‘Blackcurrant Ice’ has a dark purple corolla with yellow sepals and spurs.
‘Cameo Blue-and-White’ is extra compact with blue and white flowers. 6 in.
var. pumila is very dwarf, just 3–5 in., with blue-and-white flowers.
Aquilegia vulgaris
• blue, pink, white
• early to late spring
• 12–36 in. × 6–12 in.
• sun, part shade
• Z3–8
European columbine, Granny’s bonnet. Europe. The wild species has blue or purple-and-white flowers, but cultivars offer many other hues. Nodding flowers appear congested, with short, hooked spurs. Prefers humus-rich, moist but well-drained soils.
‘Leprechaun Gold’ has gold-marbled, bright green foliage and large, deep violet flowers borne on reddish pink stems.
‘Nora Barlow’ has tightly double flowers of red and white with very short spurs. Named for Charles Darwin’s granddaughter.
Aquilegia vulgaris ‘Nora Barlow’
‘Ruby Port’ has wine-red flowers; ‘Variegated Ruby Port’ bears similar flowers with yellow-specked foliage.
‘William Guiness’ (‘Magpie’) bears double flowers of black-purple, with white corollas, blooming from late spring through early summer.
Other Notable Cultivars
Biedermeier Mix has single and double, upward-facing blooms in violet, cream, lilac, pink, and deep red. 12–18 in. Z3–9.
Dragonfly Hybrids strain is dwarf with blue, pink, red, salmon, white, or yellow flowers. 12–18 in. Z3–9.
McKana Hybrids grow up to 24 in. tall and bear large, long-spurred flowers in a wide range of pastel colors.
Origami Series (or Butterfly Series) is a hybrid mix with bicolored flowers with slender spurs. Often listed as Aquilegia caerulea, which is a prime parent. Superior named cultivars include ‘Origami Red-and-White’ and ‘Origami Yellow-and-White’.
Brassicaceae
rock cress
Even though rock cresses are often confined to the rock garden, a number of species and hybrids are also suited to dry banks and walls, for use as groundcovers, or at the front of beds and borders to provide early spring color.
Rock cresses form mats or tufts of evergreen, sometimes hairy leaves, above which rise short stems topped with clusters of four-petaled flowers in white, pink, or rosy purple. Grow in full sun where drainage is very good to prevent winter root rot; drought is seldom a problem. Shear spent flowers after bloom time to keep a neat appearance and avoid straggly stems. Rock cress combines well with small, spring-blooming bulbs such as squills, mini-daffodils, and compact species tulips. Basket-of-gold and yellow corydalis also make attractive companions. Seldom browsed by deer.
Propagate by seed sown in spring, by softwood cuttings taken in early summer, or by division.
Arabis ×arendsii
• pink
• spring
• 4–8 in. × 12 in.
• sun
• Z4–8
Hybrid rock cress. Arabis caucasica × A. aubretioides. Evergreen mats of gray-green, hairy leaves arranged in rosettes. These can be detached and rooted after bloom time.
‘Rosabella’ has deep rose flowers, 0.5 in. across.
Arabis blepharophylla
• pink
• spring
• 4–8 in. × 15 in.
• sun
• Z5–8
Rose rock cress, fringed rock cress, coast rock cress. Coastal hills of California. Sweetly fragrant, 0.5-in., purplish pink flowers cluster atop slender hairy stems. Fuzzy leaves form basal rosettes. Tolerant of xeric conditions.
‘Frühlingszauber’ (‘Spring Charm’) is the most widely available selection. It has brilliant magenta flowers. Easy from seed; for best germination do not cover. May be listed under Arabis ×arendsii. 10 in. × 8–10 in.
Arabis caucasica
syn. A. albida, A. alpina subsp. caucasica, A. billardieri
• white
• spring
• 8–12 in. × 12–20 in.
• sun
• Z3–8, HS
Wall rock cress, Caucasian rock cress. Caucasus mountains. Grayish, 1- to 2-in. leaves form loose, low mats of foliage. In spring these are blanketed with 0.5-in., white flowers clustered at the tips of wiry stems. Shear after flowering to maintain compact growth and prevent straggliness. Short lived in warm climates; best in cooler regions.
‘Compinkie’. Bright pink flowers above compact mounds of leaves. Appropriate for troughs. 6 in.
‘Flore Plena’ (‘Plena’) has double, chalk-white flowers.
‘Snowcap’ has fragrant, pure white flowers for several weeks. Excellent as groundcover or as a skirt for spring-blooming and dark-foliaged shrubs.
‘Variegata’. White flowers and gray-green leaves rimmed with white. Striking in winter.
Arabis caucasica
Arabis procurrens
• white
• spring
• 6–12 in. × 12 in.
• sun, part shade
• Z3–7, HS
Alpine wall cress, running rock cress. Southern Europe. This species has oblong, dark green, 1-in. leaves with a glossy surface. The small, white flowers are typical of the genus. Good for containers and between pavers.
‘Glacier’ has bright white flowers that cover deep green foliage mats for several weeks. 2–4 in. Arabis sturri is very similar.
‘Variegata’ (syn. A. ferdinandi-coburgi ‘Variegata’) develops mats of broadly cream-rimmed, gray-green and pinkish leaves. Trim after bloom and check to remove any shoots that have reverted to green. Grown for its foliage. Excellent tumbling over a wall.
Araceae
Jack-in-the-pulpit, cobra lily
In recent years Jack-in-the-pulpits have become trendy, much sought after for woodland and partly shaded gardens. Anyone who has spent time in the spring woodlands of eastern North America undoubtedly remembers our native species, Arisaema triphyllum, with its curious hooded flower. This, however, has largely (except in native plant gardens) been supplanted in gardens by exciting exotic species that modern plant explorers have been discovering in Asia. These new introductions are often larger and more dramatically colored than the familiar native, but the plants’ general characteristics remain the same. The leaves, appearing with or just after the flowers, are divided into leaflets; the inflorescence consists of a slender spadix or “Jack” that bears tiny male and female flowers at the base, and is surrounded by a showy hood-like spathe or “pulpit.” The hood, often decorated with colorful stripes, is the source of these plants’ other common name, cobra lily. If the flies do their work as pollinators, Arisaema flowers are followed by dense clusters of glossy red or orange berries reputedly dispersed by ants. Remarkably, arisaemas are able to change their sex: male plants may transform into females or hermaphrodites as they increase in size and age.
Plant the fleshy tubers or rhizomes of arisaemas in neutral to acid, moisture-retaining soil rich in humus. Asian species prefer drier, well-drained soil. Although Jack-in-the-pulpits are reportedly deer resistant, others have observed heavy browsing of the berries, which are also food for birds and rodents. Protect from slugs.
Propagate by division or seed in fall or spring.
Arisaema candidissimum
• white
• early summer
• 12 in. high and wide
• part shade
• Z5–7
White Jack. Rocky banks in western China. This species produces a beautiful translucent inflorescence with a showy 5- to 6-in.-long, pink-and-white-striped spathe, pink within, and a fragrant, yellow-green spadix. A pair of three-lobed leaves, with leaflets to 2 in. wide, appears at bloom time. Clumps expand in well-drained sites.
Arisaema ringens
• purple, green
• early spring
• 10–20 in. × 20 in.
• part shade
• Z5–9
Cobra Jack. Korea, China, Taiwan, Japan. This popular species may be the easiest of the cobra lilies to grow. Each tuber produces a pair of large, glossy, trifoliate leaves, above which rises the inflorescence. The striped purple-and-green (sometimes green-and-white) spathe bends over the spadix covering it like a hood. It is further twisted, revealing its purple inside. Plant groups of tubers in soil amended with plenty of moisture-retaining organic material.
Arisaema sikokianum
• purple, white
• early spring
• 12–20 in. × 20 in.
• part shade
• Z4–9
Gaudy Jack. Japan. True to its common name, this species produces a stunningly beautiful inflorescence. The upright spathe is purplish black, surrounding a pure white, club-shaped spadix. The green or sometimes mottled leaves emerge at the same time. Plant in a sheltered spot where frost damage is unlikely to harm this early bloomer.
Arisaema sikokianum
Arisaema triphyllum
• purple, green
• spring
• 12–24 in. × 12 in.
• part shade, shade
• Z3–9
Jack-in-the-pulpit, Indian turnip, three-leaf Jack-in-the-pulpit. Damp woodlands of eastern North America. This native Jack produces a pair of trifoliate leaves below a purple, green, or striped hooded pulpit that droops at the top. The spadix may also be purple or greenish white. Round, red berries follow. Goes dormant in summer heat. Combine with other natives such as wild sweet William, green ’n gold, and blue cohosh. The tuberous roots were a staple starchy food for Native Americans.
‘Black Jack’ has green-veined, black leaves and black pulpits in late spring. 1 ft. Z6–9.
Plumbaginacae
sea pink, thrift
In the wild, sea pinks flourish in coastal areas, often growing among rocks at the high-tide mark, where they are flooded with salt water by the higher tides of spring and fall. These tough plants are tolerant of seaside gales and mountain cold, and ideal for coastal gardens. They develop rounded evergreen tufts of fine grassy leaves, green or bluish green, from which rise naked stems topped with tight globes of small pink, red, or white flowers. The foliage tufts expand slowly but not aggressively enough to make a large-scale, weed-controlling groundcover. Sea pinks thrive in very well-drained, rather poor soil; avoid fertilizing these plants, as overly rich soil promotes crown rot.
Plant sea pinks in rock gardens, as edgings, or on walls, or plant closely as a groundcover in small spaces. They also do well on green roofs, and in troughs and containers. Appropriate low-growing companions include basket-of-gold, rock cress, thymes, lavenders, and creeping bellflowers, as well as larger Russian sage, wormwoods, and fine-leaved ornamental grasses. Deadhead to encourage rebloom.
Attractive to birds and butterflies, but seldom browsed by deer. Rarely bothered by pests and diseases, although the centers of the plants may die out with age or rot; lift and separate healthy pieces from the perimeter of the clumps for replanting; discard the center. Flowers are good for small arrangements.
Divide in spring before bloom time or start seed in late winter.
Armeria maritima
• pink
• early summer
• 6–12 in. × 10 in.
• sun
• Z3–9
Sea pink, thrift. Mountains and coastal regions of the Northern Hemisphere. Foliage is mostly dark green, less than 0.75 in. wide and to 5 in. long, and forms dense evergreen tufts. Lots of stiff, 8-in. flower scapes topped with globes of pink, white, or purplish flowers emerge in summer.
‘Bloodstone’ bears large, very deep pink flowers for several weeks. Possibly a hybrid. 8–10 in. Z4–8.
‘Blue Mound’ blooms into midsummer, extending the season. Pink flowers above a mound of bluish foliage. Z4–9.
‘Cotton Tail’ is similar to ‘Alba’, but the dark green mats of foliage spread more widely. Z4–8.
‘Dusseldorf Pride’ (‘Dusseldorf Stolz’) has rosy pink flowers. 6–8 in.
‘Nifty Thrifty’ is a British introduction. It has narrow green leaves rimmed with a slender cream band, beneath pink flowers. Interesting in winter. 4–6 in. Z2–9.
‘Vindictive’ has dark green foliage and strong pink flowers from late spring to early summer. 6–10 in. Z4–8.
Armeria pseudoarmeria
syn. A. cephalotes, A. latifolia
• pink or white
• summer
• 12–18 in. × 12 in.
• sun
• Z5–9
False sea pink, plantain thrift, wide-leaf thrift. Coastal west Portugal. Lance-shaped, green leaves to 8 in. long. Large heads of pale pink or white flowers to 1.5 in. across.
Ballerina Series blooms from seed its first year and comes with flowers in red, white, and lilac (so far). Flowerheads 1 in. across are borne on 8-in. stems from early summer to early fall. The broad green leaves are similar to those of narrow-leaf plantain. Heat tolerant and good in hot, humid climates. Z6–9.
Joystick Series produces golf ball–sized flowers in red, white, lilac, and pink on 1-ft.-tall scapes. Seed started in midwinter blooms that summer. Grow as annuals in cold zones. Especially good for cutting and drying. Z7–8.
Other Notable Cultivars
‘Bees Ruby’ is a hybrid involving Armeria pseudoarmeria with broader, greener foliage than most other sea pinks. Cerise flowers in late spring to early summer. 12–16 in. × 9–12 in. Z3–8.
Asteraceae
mugwort, wormwood
This is a huge genus of herbs and shrubs, a number of which are popular, if occasionally troublesome, residents of perennial gardens, valued not only for their lacy and aromatic, silver foliage but also their toughness. Once established, they are almost drought proof, flourishing in exposed, sun-drenched spots with poor soils; in a hospitable site they are notably vigorous. This last characteristic can create problems in cultivated landscapes, because many species are prone to become invasive and gardeners are likely to find them extremely difficult to eradicate. In particular, gardeners should avoid the attractive, variegated cultivars of common mugwort, Artemisia vulgaris, such as ‘Oriental Limelight’ and ‘Variegata’; this native Alaskan species has proven tenaciously invasive throughout much of the lower 48 states.
Carefully selected and controlled, however, artemisias can make a powerful contribution. An obvious choice for dry and xeriscape sites, they also thrive in ordinary garden conditions. Keep the soil dry and avoid additional nitrogen that promotes overly lush, floppy growth. The silver foliage contrasts splendidly with scarlets, purples, and blues, and can create a sophisticated counterpoint to sun-loving shrubs and grasses. Artemisias work well in containers and their clean, astringent smell is a welcome addition to a sunny terrace or court. Though the silver foliage lends itself to use in flower arrangements, some find the fragrance overpowering indoors.
Plant artemisias in a sunny spot with well-drained, ideally sandy soil; water when dry, but avoid overwatering. The usually small flowers are not particularly attractive. Shear plants back in spring but be sure to leave enough buds on the stems to enable dense regrowth, and never cut back to the ground. Pests or diseases (except root rot in persistently damp soils) seldom trouble these plants; their bitter foliage is rarely browsed by deer or rabbits. Some species melt out in high heat and humidity, with portions of the crown rotting.
Propagate by division of established plants in early spring or by softwood cuttings taken in early summer.
Artemisia abrotanum
• yellow
• mid- to late summer
• 3–5 ft. × 2 ft.
• sun
• Z4–10
Southernwood, lad’s love, old man. Southern Europe. This Old World native is grown as a shrub in cottage gardens and mixed borders. Thread-like, grayish green foliage has a pleasant, citrus fragrance.
‘Tangerine’ produces mounds of feathery, deep olive-green foliage. To 3 ft. high and wide.
Artemisia absinthium
• yellow
• midsummer to midfall
• 24–30 in. × 30 in.
• sun
• Z4–8, HS
Wormwood, absinth. Europe, northern Africa, and western Asia. Formerly a key ingredient of the potent liqueur absinthe. Handsome finely cut, silvery gray foliage is covered in silky hairs. A popular garden plant in its native Europe, but an aggressive seeder considered invasive in some of the US western states. May melt out.
‘Lambrook Mist’ has finely divided foliage. 20 in.
‘Lambrook Silver’ has brilliant, silver foliage on arching stems. One of the best of the artemisias. To 40 in.
‘Silver Frost’ (syn. Artemisia ludoviciana ‘Silver Frost’) has compact, silvery foliage; wider than it is tall. 24 in.
Artemisia arborescens
• yellow
• spring
• 4–6 ft. high and wide
• sun, part shade
• Z9–10
Tree wormwood. Eastern Mediterranean native that flourishes in milder regions of the US Southwest. Silvery, fern-like foliage with a strong odor. Good for the back of the border, perhaps against a wall or fence in cooler regions. Inconsequential small, yellow flowers.
Artemisia californica
• yellow-green, pink
• summer to fall
• 1.5–4 ft. high and wide
• sun
• Z7–10
California wormwood. Coastal California. Woody stems and deeply divided, almost thread-like, evergreen, gray-green foliage with sweet, aromatic fragrance.
‘Canyon Gray’ is a prostrate cultivar that reaches a height of only 12–18 in. and spreads to 36–48 in.
Artemisia lactiflora
• white
• late summer to midfall
• 4–6 ft. × 4 ft.
• summer
• Z4–9
White mugwort. This Asian native develops clumps of stems with green, divided leaves and tiny, creamy-white flowers borne in attractive plumes. Rabbits can be a problem. Attractive as a border plant and cut flower, fresh for the house or dried for winter arrangements.
‘Guizhou’ has striking red-purple, almost black stems, which contrast well with the widely branched flower plumes. Sometimes granted specific status as Artemisia kitadakensis.
Artemisia ludoviciana
syn. A. palmeri, A. purshiana
• yellow
• midsummer to early fall
• 2–3 ft. high and wide
• sun
• Z4–9
White sagebrush, western mugwort. All the lower 48 states, except Florida and Alabama. Gray-white, downy, aromatic leaves are lance shaped, to 4 in. long; flowers inconspicuous. Upright clumps spread rapidly by rhizomes to colonize adjacent areas if not checked. Useful as a groundcover for sunny, droughty areas—shear such plantings in spring with a lawn mower.
‘Silver King’ is less aggressive than the species but nevertheless spreads unless kept in check. Upright grower; 0.75-in., white, woolly leaves.
‘Silver Queen’ forms a compact, well-clothed mound 2 ft. tall and 4 ft. wide. Spreading. Tends to melt out.
‘Valerie Finnis’ is the best cultivar of this species with broader, showier leaves than the species. Not as rampant. 18–24 in. × 24–30 in.
Artemisia schmidtiana
• white
• summer to early fall
• 10–12 in. × 1.5–3 ft.
• sun
• Z3–7, HS
Silvermound. Japan. Forms a low, neat, symmetrical mound of silver-green, silky haired foliage. Melts out in the US South. One of the rare, non-invasive artemisias.
‘Silver Mound’ (‘Nana’) seems to be the only type available in the nursery trade. 6 in. × 12 in.
Artemisia stelleriana
• grown for foliage
• early to midsummer
• 6–12 in. × 12–15 in.
• sun
• Z2–9, HS
Beach wormwood, dusty miller, old woman. Alaska; naturalized in the northeastern United States and the Pacific Northwest. Thrives in cultivation in all but the hottest regions.
‘Silver Brocade’ (‘Boughton Silver’, ‘Mori’) forms a spreading mat of bright silvery-white, scallop-edged, 1- to 2-in. leaves; inconsequential yellow flowers. Demands excellent drainage. Use for edging, as a groundcover, or in containers and hanging baskets; effective in sloping rock gardens and coastal gardens. Snip off any upright shoots to maintain procumbent habit.
Other Notable Cultivars
‘Huntington’ (‘Huntington Gardens’) is a hybrid with soft, filigreed, silver-frosted leaves. Fairly heat tolerant. 3 ft. high and wide. Z5–8.
‘Powis Castle’. Mostly sterile, a probable hybrid (Artemisia arborescens × A. absinthium). Dense mounds of finely divided, feathery, silver foliage 2–3 ft. tall and 1–2 ft. across. Rarely blooms. If necessary, prune to shape during active growth. Tends to spread by rhizomes into adjacent plants. An introduction from Powis Castle, Wales. Z6–9.
Artemisia ‘Powis Castle’
Araceae
arum, lords-and-ladies
Perfect to add pizzazz to the off-season garden, arums produce their often showy, undivided leaves (related Arisaema has divided leaves) from tubers in fall and retain them all winter long; they are arrow shaped and often decorated with contrasting marbling. Flowers typical of the Araceae, composed of a hood-like spathe surrounding the erect spadix, appear in spring. If pollinated, bright red berries (favorite food for wildlife) appear on the spadix above the leaves. Berry production appears to be best where summer heat is moderate. Provide well-drained but moisture-retaining soil, high in humus. The plants avoid the summer heat, becoming dormant till fall. Other perennials with attractive winter foliage, such as bigroot geranium, coral bells, pigsqueak, and sedges, make good companions in partly shaded borders. Resistant to deer.
Divide large clumps when they break dormancy, and replant the tubers at once. Seed can be collected, cleaned of its fleshy fruits, and sown in fall, but it is slow to germinate and benefits from a period of moist cold (stratification).
Arum creticum
• creamy yellow
• spring
• 18 in. high and wide
• sun, part shade
• Z8–10
Cretan arum. Crete, Greece, and Turkey. The arrow-shaped, 8- to 10-in. leaves of this species are single hued, but hold their bright green color well. The yellow or cream spathe is erect; as it matures it droops backward to reveal the surprisingly lemon-scented, school bus–yellow spadix. Selections slightly hardier than the species are available.
Arum italicum
• greenish white
• late spring
• 12–20 in. × 18 in.
• part shade, shade
• Z6–9
Italian arum. Southern Europe, Italy, Mediterranean Africa, western Asia. This woodland species is at home in shaded beds and borders, and among shrubs and trees. Bright green, arrow-shaped, 12-in. leaves boldly marked with white along the veins; greenish spathes, surrounding the bright cream spadix, appear as the foliage is withering prior to summer dormancy. A sturdy column of decorative, round, reddish orange berries follows. May self-seed but the resulting seedlings are variable, and their leaves may even be plain green. The sap can cause skin and eye irritation.
‘Marmoratum’ has large, cream-veined foliage, and 12-in.-tall, whitish flowers in spring. The leaves are striking additions to floral arrangements. Often confused with ‘Pictum’, which is similar and even considered synonymous by some. 12 in. Z4–9.
‘Winter White’ has dramatic, brightly marbled-in-white leaves, eye-catching in arrangements. The white, late-spring flowers give way to a column of bright orange berries by late summer. Blooms best in sun. 8–12 in. Z5–9.
Rosaceae
goat’s beard
Often confused with similar astilbes, goat’s beards are vigorous, clump-forming perennials with airy, plume-like blooms that inject a note of lightness into the garden. The loose, feathery, branched wands of tiny blossoms rise high above the leaves and are valued as cut flowers. Masses of dark green, divided foliage are handsome and sometimes display fall color.
Grow in partly shaded spots where the soil does not dry out readily—drought may cause leaves to become crispy and brown. The sides of streams and ponds and similarly damp places are ideal locations if the soil is rich in humus. The taller of the two species, Aruncus dioicus, is effective under trees and shrubs or as a backdrop at the back of the border. Partner with foxgloves, columbines, and late-blooming bulbs, including camassias. In native plant gardens woodland phlox, blue cohosh, wild geranium, and trilliums are appropriate companions. Pest and disease free; seldom browsed by deer.
Propagate by division in early spring or fall, or by seed sown in fall and overwintered in a protected spot.
Aruncus aethusifolius
• white
• early to midsummer
• 10–16 in. × 12 in.
• sun, part shade, shade
• Z3–9
Dwarf goat’s beard. This Korean species develops clumps of very finely divided, dark green leaves that in sunny spots become reddish in fall. Astilbe-like, creamy-white flowers bloom above the leaves. Great as a foliar contrast for small hostas in rock gardens, troughs, or at the front of partly shaded borders. Carefree and cute.
Aruncus dioicus
syn. A. sylvestris, Spiraea aruncus
• cream
• late spring to early summer
• 4–6 ft. × 2–4 ft.
• sun, part shade
• Z3–7
Goat’s beard, white goat’s beard, bride’s feathers. Europe to eastern Siberia, eastern North America. This bold clumping perennial prefers high-humus woodland soils and should not be allowed to dry out. Tolerant of sun, but intense sun burns the foliage even with extra irrigation. Erect and shrub-like, the branching stems bear an abundance of two- or three-times divided leaves with oval leaflets, doubly serrated along their edges. Tall, feathery plumes of creamy-white flowers, up to 20 in. long, rise well above the foliage mass. Male and female flowers are borne on separate plants; the male flowers tend to be showier and fluffier. Appropriate for native plant, wild, and meadow gardens, along stream banks, and around ponds. Mass, group, or grow as a specimen. The rootstock becomes very tough and woody with age—if you plan to increase stock by division, you may need a machete.
‘Kneiffii’ has much more deeply cut, almost thread-like foliage. Good for smaller spaces in moist soil. 2–3 ft.
Other Notable Cultivars
‘Guinea Fowl’ (Aruncus dioicus × A. aethusifolius). Neat, compact clumps of leaves, more dissected than those of A. aethusifolius. Inflorescence a delicate spray of tiny white flowers. Best in light shade. 12–18 in. Z5–7.
‘Misty Lace’, also a hybrid of A. dioicus × A. aethusifolius, tolerates full sun and is somewhat hardier that ‘Guinea Fowl’. This hybrid displays intermediate characteristics of its parents. Better than others for hot and humid gardens. An Allan Armitage introduction. 18–24 in. Z4–7.
syn. Hexastylis, Heterotropa
Aristolochiaceae
wild ginger
Rhizomes of the wild gingers have a spicy fragrance that recalls the culinary spice, but the two groups of plants are not related. Despite the advice offered by some wild food enthusiasts, do not use wild ginger to flavor your cuisine, as some species in this genus contain aristolochic acid, which according to the US Food and Drug Administration can cause serious and permanent kidney damage. Instead, enjoy these woodland perennials in the garden, where their large, kidney-shaped leaves furnish an elegant and shade-tolerant groundcover. Most species are evergreen or nearly so (some botanists have split the genus, moving the evergreen species into Hexastylis). The foliage is more of a presence in the garden than the calabash pipe- or cup-shaped flowers, which, though intriguing, are modest in size and commonly hidden beneath the leaves.
Most wild gingers prefer moist but well-drained, humus-rich soils with a neutral to acid pH. Typically they flourish on woodland sites, and though they appreciate regular irrigation during hot, dry weather, most are reasonably drought resistant once well established. They spread by creeping, fleshy roots or rhizomes, slowly forming expanding clumps or patches. Because even the deciduous wild gingers keep their foliage throughout the growing season, they make good companions for spring ephemerals such as spring beauties, trilliums, and trout lilies. The evergreen species are excellent as container plantings year-round.
Deer resistant; the only serious pests are slugs or snails.
Beyond the species featured here, the Asian Asarum splendens and its large-leaved cultivar ‘Quicksilver’, A. maximum and its selections ‘Green Panda’ and variegated ‘Ling Ling’, and our western US native A. hartwegii (syn. A. marmoratum) are also interesting and worth seeking.
To propagate, collect seeds in summer as soon as they ripen and sow in pots to overwinter in a cold frame or sheltered spot; or divide mature clumps into well-rooted pieces 6–8 in. across in early spring or fall. Alternatively, wash the soil from rhizomes and use a sharp knife to slice them into pieces, each including two leaves or a node; plant rhizome cuttings shallowly, with leaf-bearing end exposed; mulch to keep moist.
Asarum arifolium
• brown
• late spring
• 6–8 in. × 12 in.
• part shade, shade
• Z4–8
Arrow-leaf ginger. Southeastern United States. Evergreen with smooth, variably mottled, triangular or arrow-shaped leaves to 8 in. long. Beige-brown flower buds are visible among last year’s leaves in early spring; they open to little brown jugs usually with spreading lobes. Handles heat and humidity with aplomb.
‘Beaver Creek’ may have more vigor. A Mt. Cuba Center, Delaware, introduction.
Asarum asaroides
• purple-brown
• spring
• 4 in. × 15 in.
• part shade
• Z5–9
Asarum leaf, perennial wild ginger. Reliable and vigorous Japanese native that quickly forms 15-in.-wide clumps of evergreen, heart-shaped leaves marked with silver, to 6 in. long. At the base of the plant, 2-in., dark purple-brown flowers emerge in spring. Very easy to grow.
Asarum canadense
• purple-brown
• midspring
• 6–12 in. × 1–1.5 ft.
• part shade, shade
• Z3–8
Canadian wild ginger. Eastern half of North America, from Manitoba to North Carolina. An undemanding, deciduous species with downy, heart- to kidney-shaped, matte dark green leaves to 6 in. across; cup-shaped, purplish brown flowers are 1 in. wide.
‘Eco Choice’ has somewhat denser foliage.
Asarum caudatum
• maroon, white
• late spring to early summer
• 2–8 in. × 3 ft.
• part shade, shade
• Z5–10, HS
Western wild ginger, long-tailed wild ginger. Moist forests from British Columbia through southern California and eastward into Montana. Shiny, evergreen, heart-shaped leaves, 2–5 in. across; drought tolerant once established. Cup-shaped, three-lobed flowers end in long, graceful tails. The form album has creamy-white flowers.
Asarum europaeum
• purple-brown
• midspring
• 6 in. × 8–12 in.
• part shade, shade
• Z5–9
European wild ginger. Finland to Macedonia, France, and Italy. Slow to spread but perhaps the most elegant of the wild gingers with its dense cover of glossy dark green leaves. Excellent for woodland gardens but also for edging shady borders. Self-sows sparingly in hospitable locations. Protect from slugs. Avoid planting too deeply.
• purple-brown
• midspring
• 6–9 in. × 6–12 in.
• part shade, shade
• Z6–9
Shuttleworth ginger. Moist woodlands in the Appalachian mountains. This species may offer the most beautiful foliage of all: silver mottling on the leaves creates a pattern almost like fish scales. Slow to spread, but lovely as an edging plant in a shady border, a groundcover, or container specimen.
‘Callaway’ is tighter than the species, with good-looking mottled leaves. Very slow to bulk up. Introduced by Fred Galle at Callaway Gardens, Georgia.
‘Velvet Queen’ has the same distinguished leaves as ‘Callaway’ but is larger and bulks up more quickly.
Apocynaceae
milkweed
It may seem counterintuitive to include a plant in your garden because of its ability to attract insects, but for many, that is the most persuasive argument for planting milkweeds. Several species do bear attractive, even showy flowers, and most are hardy and reliably perennial given an appropriate site. But what makes them really special is that they serve as nurseries for the caterpillars that metamorphose into monarch butterflies.
The common name for this genus refers to the milky appearance of its sap, which in many species is toxic. By feeding on milkweed leaves, monarch butterfly larvae (caterpillars) make themselves poisonous, thus protecting themselves against birds and other predators. The toxicity of asclepias plants makes them resistant to deer, rabbits, and squirrels. Some species have been esteemed as medicinal, although all parts of the plant are toxic in quantity unless cooked. Gardeners with sensitive skin should protect themselves with gloves when working around these plants.
Milkweeds form clumps of sturdy, fibrous stems with ovate to blade-shaped, generally leathery, green leaves, and dense, rounded, or flat-topped clusters of flowers at stem tips and leaf axils. The flowers attract many different butterflies in addition to monarchs. Prolong bloom time of individual plants by deadheading before seed set; to encourage a second crop of flowers, cut plants back after the first flush of bloom. The fat or skinny, spindle-shaped seedpods that follow split when ripe to release seeds equipped with gossamer parachutes that aid dispersal by wind.
With the exception of a few species adapted to wetland habitats, milkweeds thrive in full sun in almost any well-drained garden soil, even nutrient-poor ones. Pinch off the tips of new shoots when they are 5 in. tall to encourage bushiness. Fungal and bacterial leaf spots may attack milkweeds in hot and humid conditions.
An obvious choice for butterfly and wildlife gardens, milkweeds are also at home in meadow gardens, while the more refined cultivars hold their own in mixed borders. They make bright and long-lasting cut flowers; sear the base of the stem with a flame to seal in the sap.
Propagate in containers to obviate root disturbance at planting time. Sow scarified seed outdoors in fall, or stratify and start indoors in early spring. Spring basal cuttings root readily in sand; milkweeds are taprooted and do not respond well to division.
Asclepias curassavica
• scarlet, orange
• early summer to fall
• 2–3 ft. × 1.5–2 ft.
• sun
• Z9–11
Blood flower, Mexican butterfly weed. Tropical Central and South America. Often grown as an annual in colder climates. Showy flowers borne over a long season attract hummingbirds and bees as well as butterflies. Self-seeds prolifically in warmer southern areas of the United States, becoming invasive. A valuable cut flower.
Close-up of Asclepias curassavica
Asclepias incarnata
• pink, white
• early to late summer
• 4–5 ft. × 2–3 ft.
• sun
• Z3–6
Swamp milkweed. Across the United States as far west as the Rocky Mountain States. A wetland species that is ideal for rain gardens, or pond and stream banks, but which also tolerates better-drained soils in garden borders. Clusters of small, fragrant flowers, usually pink to mauve but occasionally white, followed by interesting long pods. Attracts hummingbirds, butterflies, and bees.
‘Cinderella’ bears exceptionally large clusters of pink, vanilla-scented flowers from midsummer to early fall.
‘Ice Ballet’ has pure white flowers that contrast dramatically with butterfly visitors. 3- to 5-ft. tall.
Asclepias purpurascens
• pink, purple
• late spring to midsummer
• 2–3 ft. × 1–3 ft.
• sun, part shade
• Z3–9
Purple milkweed. Eastern North America from New Hampshire to North Carolina, west to Minnesota and Arkansas. Tolerates poor, dry, and rocky soils. A vigorous spreader, it often forms large colonies; not suitable for flower borders but an asset in native plantings, meadows, or open woodlands. Rose pink to purple flowers.
Asclepias tuberosa
• orange, yellow
• midsummer to early fall
• 1–2.5 ft. × 1–1.5 ft.
• sun
• Z3–9
Butterfly weed, pleurisy root. Eastern and southwestern North America. The showiest of the milkweeds, bears clusters of brilliant orange or yellow flowers from midsummer. Butterfly weed performs well in ordinary garden soils, but once established, this tough plant also thrives on poor, dryish soils that do not become waterlogged. Not an aggressive spreader.
Gay Butterflies is a hybrid mix with blooms in red, orange, or yellow. Especially good for cut flowers. 24–30 in.
‘Hello Yellow’ has lively yellow flowers. 24–30 in. tall.
Asclepias tuberosa
Asphodelaceae
Jacob’s rod
These stately plants, which supposedly grew in the Elysian Fields, provide strong vertical accents in the garden. Jacob’s rods increase in size slowly, the rhizomatous roots eventually forming large clumps. The triangular, grassy basal leaves and the spirally arranged stem foliage have a fresh green appearance and retain their good looks into fall. The flowers and, later, the fruiting spike may be cut and dried for use in winter arrangements. To harvest the seed, crack open the conspicuous round seedpods when they have ripened.
Average or even poor soil is fine as long as it drains freely; Jacob’s rods tolerate drought conditions readily. Heavy clay soils that remain wet in winter, however, are likely to prove fatal. Protect dormant plants with a winter mulch in colder zones.
To propagate, divide large clumps after flowering has ended or harvest and sow seed, which germinates readily, in fall.
Asphodeline liburnica
syn. Asphodelus liburnicus
• pale yellow
• midsummer
• 24–30 in. × 12 in.
• sun
• Z6–10
Jacob’s rod. Southeastern Europe. This upright, clump-forming perennial bears blue-green leaves on the lower part of the stems only. Flower stems arise in midsummer to support loose, 8-in. spires of starry, 2-in., pale yellow flowers striped on their backs with green. Interesting knobby seedpods follow. Suitable for dry meadows and large rock gardens, where yarrows and purple sages make fine companions.
Asphodeline lutea
• yellow
• late spring to early summer
• 3–6 ft. × 1–2 ft.
• sun
• Z6–9, HS
King’s spear, Jacob’s rod, yellow asphodel. Grasslands of Eastern Mediterranean region, Turkey, and the Caucasus. Makes untidy clumps or rosettes of long, bluish leaves from which rise leafy unbranched stems topped with dense, 12- to 18-in. racemes of highly fragrant, yellow flowers. These are showy, star shaped, and 1 in. or so across, with prominent stamens. Plant in groups or drifts for best effect. In dry meadow plantings they assort well with little bluestem and other blue-foliaged grasses; in xeriscapes partner with lavenders, sages, and artemisias; dwarf blue spruce makes a stunning background. Protect from slugs, but otherwise pest and disease free; may be browsed by deer.
Asphodelaceae
asphodel
Native to open meadows, rocky waste- and scrublands in central Europe, and Mediterranean regions and as far east as the Himalayan Mountain range. These plants bear their white or pale pink flowers in erect spikes on leafless, unbranched stems (scapes); the blossoms are accented by brown or pink veining on the reverse of each petaloid tepal. Asphodels perform best on moderately fertile soils. Note that 18-in.-tall Asphodelus fistulosus (syn. A. tenuifolius), onion grass, has become an invasive alien in the canyons and coastal ranges of California.
Susceptible to aphids, but otherwise free of pests and diseases including deer and rabbits.
Propagate by seed sown in spring (do not cover), or by division of plants while dormant.
Asphodelus albus
• white
• early summer
• 3–5 ft. × 1 ft.
• sun, part shade
• Z7–11, HS
White asphodel. Found in shallow soils around the Mediterranean, white asphodel produces showy spikes of white flowers on thick stems. Each tepal has a single brown stripe on the reverse that produces a slightly pink effect. The grassy, mid-green foliage is keeled and flattened; leaves sometimes reach a length of 24 in. Deadhead fading flowers unless seeds are wanted, as the spikes become shabby looking when left on the plant; if allowed to mature, they will throw countless seedlings the following season. Excellent in California and in dry soils elsewhere, but not in the hot, humid Southeast. Group in sunny spots among shrubs, or in wild gardens, meadows, and rough grass.
Asparagaceae
cast-iron plant
This genus illustrates one of today’s most exciting trends in American gardening: over the past generation gardeners in the southern United States have built on their local traditions to make the region a horticultural hotspot, and in the process our national plant palette has broadened immensely. A couple of decades ago, aspidistras were known as little more than “cast-iron” parlor or houseplants; only ten or so species were recognized worldwide. As southeastern landscapers increasingly demanded aspidistras, plant explorers searched and discovered in excess of 80 previously unknown species in their Asian homeland. This genus is now among the most dynamic foliage plants in the nursery trade.
The attraction of aspidistras is not only their bold evergreen foliage, leathery and broad bladed, but also their extraordinary tolerance for difficult hot, humid summers. Aspidistras thrive in heat and humidity, yet tolerate significant cold—some species can survive a dip into the mid-teens (°F) or even lower. Such a cold snap may kill the foliage to the ground, but new leaves will emerge from the roots. Once established, aspidistras do well in dry shade too, ideal for regions such as central Texas, where summer often brings drought. Susceptible to mealybugs and spider mites, but infestations are rarely serious; deer resistant. Aspidistras’ tolerance for neglect is legendary—these are the ultimate low-maintenance perennials.
Borne singly at ground level, and commonly hidden under the foliage, aspidistra flowers are intriguing with an odd, almost starfish or sea anemone–like form. Floral designers prize the long-lasting foliage.
Moist but well-drained soil produces the most vigorous growth. Avoid overwatering or overfeeding; a nutrient-poor soil encourages the best foliage color. Deeply dug, organic-enriched, acid loam suits these plants best, although they adapt to a wide range of soils, and are moderately salt tolerant. Partly or fully shaded sites are preferred; aspidistras tolerate direct sunlight if shaded at midday. Excessive sun results in yellowing leaves.
Interesting species not described below include slender-leaved Aspidistra linearifolia, yellow-spotted A. crispa, A. hainanensis and its cultivar ‘Jade Ribbons’, and yellow-flowered A. attenuata from Taiwan. Collectors will want to seek out these and others. Though tough and virtually foolproof, aspidistras are very slow growing. Propagate by division but expect offspring to require two or more years to bulk up. Start species from seed, but be prepared to wait a decade for maturation.
Aspidistra elatior
• cream
• late spring to early summer
• 2–3 ft. × 1–2 ft.
• part shade, shade
• Z7–11
Cast-iron plant, barroom plant. China and Japan. Evergreen, with lustrous, long-stemmed and arching, lanceolate, dark green leaves to 24 in. long by 4 in. wide. Insignificant purple-spotted, creamy flowers, deep red within, may appear at soil level. Overwinters outdoors in zone 7b with protection.
‘Asahi’ has bold green leaves, to 30 in. long and 5 in. wide; the tips mature to striking white.
‘Fuji No Mine’ boasts glossy, dark leaves, 3 ft. long and 5 in. wide, accented with a central creamy-yellow streak.
‘Milky Way’ (‘Amanogawa’) forms a dense clump of leaves, 18 in. tall and 2 in. wide, striped and freckled with white and yellow.
‘Okame’ has upright leaves with bold, vertical, white striping. 30 in.
‘Spek-tacular’ has 40-in.-long leaves abundantly flecked with yellow, and arched at the tips.
Aspidistra elatior
Aspidistra guangxiensis
• purple
• spring to summer
• 18 in. × 12 in.
• part shade, shade
• Z8–11
Cast-iron plant. Guangxi region of China, a new introduction available chiefly as the selection ‘Stretch Marks’. It has medium green leaves, 3 in. wide by 10 in. long, speckled heavily with oval, creamy-yellow spots. The flowers have an uncanny resemblance to sea urchins with grape-purple centers ringed by yellow-green tendrils. Overwinters outdoors in zone 7b, though the leaves die back.
Asteraceae
aster, Michaelmas daisy
Once a sprawling genus of some 600 species, recently asters have been reorganized by botanists so that all except one of the North American members have been assigned to other genera (Eurybia, Symphyotrichum, Doellingeria, etc.). For convenience sake, the reassigned species’ former names are included in this book’s index.
However you name them, this invaluable, colorful group of plants includes many tough and persistent species. Some, like the attractive Siberian Aster tataricus, can be too successful, even invasive, and need a large space in the landscape; others are well-behaved stalwarts of summer and fall displays in gardens of all kinds. Asters bear composite daisy flowers, typically in great abundance, with petals (ray flowers) in shades of blue, purple, white, and pink. The centers (disks) of each blossom (actually a head of flowers composed of countless individual flowers) are usually yellow. As a rule, asters and their kin prefer a well-drained, organic-rich soil, and struggle if planted in dense clays; they do well in coastal, sandy soils. Full sun is best for most species, though some tolerate part shade. Taller species benefit from being cut back by half before midsummer to promote branching and more compact growth that can forgo staking. Asters are prone to foliar diseases including powdery mildew and rust, as well as some insect pests including aphids, leafhoppers, and spider mites. Though such infestations rarely kill the plants, they disfigure them and may affect garden neighbors. Search out disease- and pest-resistant cultivars. Deer seldom browse asters; butterflies flock to their flowers.
Propagate by division of mature clumps in spring or fall, or start seed indoors in late winter. Softwood stem cuttings taken in late spring root readily.
Aster ×frikartii
syn. A. amellus × A. thompsonii
• lavender
• early summer to fall
• 2–3 ft. × 1.5 ft.
• sun, part shade
• Z5–10, HS
Frickart’s aster. This hybrid isn’t as pest and disease resistant as some of the species, but it blooms early and long from late spring to midfall if deadheaded conscientiously. Vivid, fragrant flowers, 2.5 in. wide, top loose mounds of dark green, oval leaves. Protect dormant plants with mulch of evergreen boughs through winter in cold zones; well-drained soil is essential. Superb for containers.
‘Flora’s Delight’, an introduction by Alan Bloom, is more compact (1.5–2 ft.) with 2-in., lilac-colored flowers. Somewhat less cold hardy than other members of this group.
‘Monch’ bears 2-in., lavender flowers with yellow centers. 2 ft. tall.
Aster ×frikartii ‘Monch’
‘Wonder of Staffa’ has slightly paler lavender flowers but is hard to distinguish from ‘Monch’. 2 ft.
Aster tataricus
• blue
• mid- to late fall
• 3–6 ft. × 3 ft.
• sun
• Z3–9
Tatarian daisy. Siberia. Among the latest to bloom, this species is notable for seldom needing staking. In late summer to fall, bristly flower stalks arise from a basal mass of thick, spinach-like, 2-ft. leaves. Sessile leaves clothe the stems that branch in their upper reaches. Numerous yellow-eyed, blue to purple daisies bloom until weather becomes too cold. Spreads freely. Divide every few years to control its invasive tendencies as well as for propagation.
‘Jindai’, a selection by plantsman Rick Darke, is similar but on shorter stems. 3–4 ft.
Aster tongolensis
• blue, purple
• early summer
• 1–1.5 ft. × 1 ft.
• sun
• Z3–9
East Indies aster. Western China. Stoloniferous and mat forming, with oval leaves in a slowly spreading cushion; in early summer, erect, thick, and hairy, almost leafless stems branch at the top, and bear solitary, 6-in.-wide, violet-blue flowers centered with orange-yellow. Ideal for rock gardens, troughs, and the front of borders.
‘Berggarten’ blooms prolifically with 2- to 3-in.-wide, orange-eyed, bright violet-blue flowers. 24 in. tall.
‘Napsbury’ has light violet-blue flowers with slender rays. 18 in.
‘Wartburg Star’ is 1.5–2 ft. high and wide, with long-blooming, 2-in., violet-blue flowers.
Saxifragaceae
astilbe, plume flower
A moist shaded garden without astilbes is like a cock without its crow! Their beautiful fluffy plumes of pink, red, purple, or white flowers and attractive fern-like leaves would earn them a place even were it not for their tolerance of shade and easy-care ways. And as a bonus, deer don’t seem to find them tasty.
Astilbes are indigenous to damp woodlands and streamsides in China and Japan, as well as the United States (e.g., Astilbe biternata). The bulk of the named selections on the market are the result of extensive hybridization between species. Clumps of astilbe grow from a mass of rhizomes that becomes woody with age. Young foliage, two- or three-times divided into toothed leaflets, erupts in spring. Leaf color is variable, mostly dark or mid-green; red-flowered selections often display young, deep red foliage. Fluffy plumes of tiny flowers are borne mostly above the foliage mass in summer on leafless stems of varying heights. Bloom time runs from late spring (early) through to mid- to late summer (late). Catalogs may list selections as early, midseason, or late. Seedheads and leaves become an attractive rusty brown and can provide interest through the winter months. Allowed to remain intact, these provide unusual contrast to early-blooming stinking hellebores or Italian arum, for example, and are interesting in dried flower arrangements.
Provide rich, acid soil that remains moist but does not become waterlogged; be sure plants remain well watered in hot weather, as drying out results in crisping of the leaf margins. Amend the soil with plenty of organic matter as astilbes are greedy feeders; an annual dressing of rotted manure or compost is beneficial. Divide the woody rootstocks every three to four years in spring or fall to maintain vigor or to propagate.
Astilbes are often major players in moist, shaded beds and borders, and beside streams or ponds, where they may be massed to provide large drifts of color or grouped with other shade lovers. Among their most popular companions are bold-leaved hostas, hellebores, lungworts, hardy begonias, and ferns. The tall types look well among flowering shrubs, especially early- or late-blooming ones to extend the season of interest. Both compact and tall astilbes grace any container solo or mixed with others plants that like damp feet.
Pests and diseases are few, although leaf spots and mildew may damage the foliage. Ignored by deer and rabbits.
Increase by dividing the clumps in spring; pot up or replant at once.
Astilbe ×arendsii
• red, pink, white, purple
• late spring to midsummer
• 2–4 ft. × 2 ft.
• part shade
• Z3–8
Hybrid astilbe. This hybrid group displays amazing variety in all aspects, and includes the bulk of available cultivars. Flowering time varies from early to late, enabling gardeners to have color over many weeks.
A partly shaded bed with cultivars of Astilbe ×arendsii
‘Amethyst’ has robust lavender plumes. Early to late. 18–24 in.
‘Bridal Veil’ (‘Brautschleier’). Thick plumes of white flowers. Midseason. 18–24 in.
Astilbe ‘Bridal Veil’
‘Deutschland’ may be the whitest of whites, not turning ivory. A strong grower. Early.
‘Fanal’. Dark red flowers bloom above bronzy foliage. Early. 24 in.
‘Montgomery’ has bright red plumes with green foliage. Midseason. 20–24 in.
Music Series blooms mid- to late season: ‘Jump and Jive’, bright pink with dark foliage, 12–16 in. ‘Rhythm and Beat’, fuchsia pink with medium green leaves, 14–18 in., reblooms. ‘Rhythm and Blues’, hot pink over dark leaves, 20–24 in. ‘Rock and Roll’, black-stemmed, white plumes above bronzy leaves; 18–24 in.; reblooms.
Astilbe ‘Rhythm and Blues’
‘Peach Blossom’. Light salmon-pink flowers. Reliable old variety, often listed under Astilbe ×japonica or A. ×rosea. 24 in. Z4–9.
‘Prof. van der Wielan’ has open plumes of white flowers. Late. 30–48 in. Z4–9.
‘Straussenfeder’ (‘Ostrich Plume’) has elegant branched, pendulous inflorescences of hot-pink flowers. Tolerates heat and humidity. Has A. thunbergii blood. 3 ft.
• white, pink
• mid- to late summer
• 10–36 in. × 24 in.
• sun, part shade
• Z3–8
Chinese astilbe. Siberia, China. Vigorous, with bronzy, softly hairy leaves divided into three rounded leaflets rimmed with double teeth. The species is seldom cultivated, but there are plenty of superior selections.
‘Diamonds and Pearls’ has dense plumes of pure white flowers above dark green foliage. Heat and humidity tolerant. 2 ft. tall.
‘Finale’. Leaves are bronzy green and lacy. Lavender-pink flowers. Appropriately named, blooming into early fall. 15–18 in.
‘Maggie Daley’. Bright fuchsia-pink plumes over green foliage. A strong grower. Midseason. 28 in.
‘Pumila’ has lilac-pink plumes on 10-in. stems. Good groundcover if kept damp, but often displays unattractive half-spent plumes. May be a hybrid. Fast spreader. Late.
‘Visions’ is compact with upright bright raspberry flower plumes. Bronze green foliage. Mid- to late season. 15 in. Others in the excellent Visions Series include pale ‘Visions in Pink’ (18 in., mid- to late season) with bluish green leaves, ‘Visions in Red’ (15 in., midseason), with bronze foliage, and ‘Visions in White’ (20–30 in., early) with soft white plumes.
Astilbe ×crispa
• pink
• early to midsummer
• 6–10 in. × 10 in.
• part shade, shade
• Z4–8
Crisp-leaved hybrid astilbe. This diminutive hybrid has crimped, deep green leaves below a full complement of fluffy flower plumes. Excellent for rock gardens, containers, or as edging along shaded pathways
‘Lilliput’ has light salmon flowers. 6–8 in.
‘Perkeo’ (‘Peter Pan’) has deep rose-salmon plumes. 8–10 in.
Astilbe simplicifolia
• pink, white, magenta
• early to midsummer
• 12–18 in. × 24 in.
• sun, part shade
• Z3–8
Star astilbe. Japan. This short species is best known for its contribution as a parent to many superior hybrid selections:
‘Key West’ has mounds of dark burgundy leaves, with feathery plumes of carmine red. Excellent for cutting and in containers. Midseason. 16–20 in.
‘Pink Lightning’. Open, pale pink plumes over dark lustrous leaves. Early. 16–20 in.
‘Sprite’ is a favorite, with airy shell-pink flower plumes and bronzy leaves. Late. 12 in. An Alan Bloom selection. Perennial Plant of the Year 1994.
Astilbe simplicifolia ‘Sprite’
‘White Sensation’ is particularly compact with 10-in. mounds of glossy green foliage. Dainty white flowers. Mid- to late season. 18 in.
Saxifragaceae
shieldleaf
This genus boasts just a single species, but for gardeners who love drama, it’s a must-have plant. It has its limitations, however: it does not thrive in hot regions or where the soil dries out. Provide moist soil and at least a partially shaded site. Mulch in summer to retain soil moisture. Plant alongside a stream or in a low-lying wet spot, or use it to frame a pool or pond. Spectacular in a bed or border, or as a solo container specimen. Ferns, hostas, cardinal flowers, and astilbes are handsome companions.
Foliage may be affected by late spring frosts, but new leaves will develop. In fall, refrain from cutting back too early as there is often beautiful yellow fall color. Protect against slugs.
Propagate by sowing seed in fall or divide mature plants in early spring as the foliage emerges.
Astilboides tabularis
syn. Rodgersia tabularis
• white
• summer
• 3 ft. × 3–4 ft.
• part shade, shade
• Z5–7
Shieldleaf. Veteran gardeners may recognize this plant by its former name, Rodgersia, and once you’ve seen it you certainly won’t forget it. A native of northeast China and Korea, it bears 2-ft.-wide, ruffle-edged, parasol-like leaves atop furry, 3-ft. stems, creating a dense, tropical-seeming canopy of vegetation. In midsummer it sprouts even taller plumes (even up to 5 ft.) of creamy-white flowers that could be mistaken for an astilbe on steroids.
Astilboides tabularis
Apiaceae
masterwort
A border filled with all the usual floral suspects may be colorful, but also predictable; including a drift or even just a group of masterworts, with their quirky elegance, is a sure remedy. Though still uncommon in American gardens, these plants featured in British cottage gardens as early as the 17th century. The starburst-like heads of small, sweetly scented blossoms are backed by a ruff of bracts that would look quite at home around the neck of some Jacobean dandy. Attractive though not striking parsley-like foliage forms mounding basal rosettes that are handsome backdrops for the flowers. In temperate climates astrantias bloom from late spring into early fall; where summers are hot, bloom peters out in early summer.
Masterworts have earned their enduring popularity by the ease with which they are grown. Relatives of Queen Anne’s lace, they have a similar ability to thrive in a wide range of soils, even fairly heavy clay; on such sites, dig in plenty of organic matter to ensure consistent moisture. Though masterworts perform best on well-drained soils, they tolerate wet ones well. They thrive in sun or part shade; where summers are hot, shelter from early afternoon sun. Best where night temperatures drop below 70°F in summer. No serious pests and resistant to deer; reputed to repel slugs, and so protect susceptible neighbors.
Aside from the dash of novelty their flowers add to a humdrum bed or border, masterworts are useful as authentic elements for a cottage garden, and they are a source of intriguing cut flowers for fresh or dried arrangements. Their leaves make an attractive contrast to bold-textured hostas and ligularias. In addition, the flowers entice insects and butterflies.
Propagate by division of established clumps in spring, or sow fresh seed into pots or trays in fall and allow to overwinter outdoors.
Astrantia major
• white
• summer
• 24–36 in. × 12–18 in.
• sun, part shade
• Z4–7
Great masterwort. Europe and western Asia. This is the most popular ornamental astrantia, offering many fine cultivars.
‘Claret’ bears dark red flowers on black stems. To 30 in. tall.
‘Hadspen Blood’. Vigorous, with very dark red flowers. Introduced from Hadspen House, England. 30 in.
subsp. involucrata ‘Shaggy’ (‘Margery Fish’) has pink-tinged, white-and-green flowers with fringed, green-tipped white bracts.
‘Moulin Rouge’ bears green-and-red flowers; pointed, deep red bracts are tipped with purple-red. Sometimes reblooms in fall if cut back after first flush. 18–24 in.
‘Primadonna’ has 1.5-in., silvery rose flowers with maroon-tipped bracts. Long blooming. 24 in. Z6–9. A sport, ‘Vanilla Gorilla’, has bluish green leaves irregularly edged with white; soft pink flowers.
Astrantia major ‘Primadonna’
‘Star of Beauty’. White-and-purple flowers, white bracts tipped deep dusty purple.
Brassicaceae
false rock cress
No self-respecting spring rock garden should be without false rock cress—its evergreen, small, sometimes toothed, and often hairy leaves creep across the ground in a neat, compact carpet, and for several weeks each spring it is smothered with brightly colored, four-petaled, cross-shaped flowers. Moderately fertile, well-drained soil with a neutral to alkaline pH is ideal. When established, false rock cress handles drought well. Shear hard after bloom before seed set to restrain seed production, both for the sake of neatness and to preserve the plant’s vigor. False rock cress is short lived and does not adapt well to summer heat. In hot climates it is often treated as a biennial. Watch for aphid infestations.
Outside the rock garden, false rock cress is excellent tumbling over walls, among paving stones, or at the front of sunny beds. It is colorful spilling from hanging baskets and containers in early spring, perhaps mixed with polyanthus primroses, forget-me-nots, pansies and violas, or English daisies. Basket-of-gold, white-flowered rock cress, and miniature spring bulbs including daffodils, grape hyacinths, and checkerboard lily are fine companions also. An attractive underplanting for spring bedding displays. Deer resistant.
Some selections come true from seed. Propagate those that don’t from new growth that appears after deadheading, or divide in fall.
Aubrieta deltoidea
• various
• early spring to spring
• 2–6 in. × 12 in.
• sun, part shade
• Z5–7, HS
False rock cress, rock cress, aubrietia. Mediterranean to central Asia. This species has been used extensively in breeding, with the result that most selections on the market are hybrids. They may also be listed as Aubrieta ×cultorum.
‘Aureovariegata’. Mauve-purple flowers above grayish leaves irregularly edged with yellow.
‘Barker’s Double’ bears double, purplish blue flowers.
‘Red Cascade’ belongs to the Cascade strain. The flowers are magenta-red. ‘Blue Cascade’ is deep lilac-blue, ‘Purple Cascade’ is rich purple. Can be started from seed.
‘Silver Edge’ (‘Silberrand’). Indigo-blue flowers over green foliage, crisply rimmed with white.
‘Whitewell Gem’ has purple to violet blooms. Comes true from seed.
Aubrieta deltoidea ‘Whitewell Gem’
‘Variegata’ has gold-variegated leaves and lavender-blue flowers. Not very robust.
Brassicaceae
basket-of-gold
Like its close relatives Aubrieta and Arabis, this genus provides a host of spring-blooming prizes for rock gardens, for spilling over walls, and for tucking into crevices. Woody at the base, basket-of-gold’s upper growth forms loose clumps of evergreen, grayish, spoon-shaped leaves to 5 in. long. This superstructure bears masses of brilliant school bus–yellow flowers that bloom over several weeks from spring into early summer. Best in full sun, basket-of-gold thrives in well-drained, poor to average soil but is not fussy as long as the roots do not remain wet; rich soil promotes soft, leggy growth, susceptible to insects. Established plants are drought tolerant. Shear after bloom for neatness and to ensure vigor.
Sow seed in late fall outdoors or with protection in very early spring. Named cultivars must be propagated vegetatively: summer cuttings usually root easily, but attempting division in fall is not reliable.
Aurinia saxatilis
syn. Alyssum saxatile
• yellow
• spring to early summer
• 8–12 in. × 12–18 in.
• sun
• Z3–8, HS
Basket-of-gold, goldentuft, madwort. Southeastern and central Europe. This cheerful plant is easy to grow and provides dramatic spring color. Rather floppy foliage is mostly grayish, felted with hairs, and a perfect foil for the flowers. Replace old woody plants with young stock; plants may self-seed freely unless cut back before seed set. In hot, humid regions, it is best grown as an annual.
‘Citrinum’ (‘Luteum’, ‘Sulphureum’) has pale lemon-yellow flowers.
‘Compactum’ is a 4- to 8-in. miniature form. ‘Compactum Flore-Pleno’ (‘Plena’) has double flowers.
‘Dudley Neville Variegated’ has cream-edged foliage and is beautiful throughout the season, especially with yellow corydalis. Apricot buff flowers. In hot climates, provide midday shade, or treat as an annual.
‘Golden Flourish’ was bred for container cultivation. Masses of mustard-yellow flowers above green foliage. Eye-catching spilling over the edges of planters with tulips, pansies, daffodils, and other early bloomers.
‘Sunny Border Apricot’ has soft orange-yellow flowers. A Sunny Border Nursery introduction. Z6–9.
Fabaceae
false indigo, wild indigo
Although well known to Native Americans who used false indigo as a source of blue dyes, this genus has only recently found a major place in US gardens. Native to eastern and midwestern North America, baptisias vary in stature and flower color, but in general bear pea-like flowers in showy spikes in spring, and trifoliate, commonly blue-green leaves. The leaves are arranged alternately on stems that cluster in dense, shrub-like groups. Baptisias’ naturally neat form and tolerance for poor soils, even clays and rocky ones, as well as drought, has made them staple plantings over the last decade. As their popularity has grown, they’ve attracted interest from plant hybridizers, especially at the Chicago Botanic Garden and North Carolina Botanical Garden. A steady stream of refined and floriferous cultivars and hybrids have appeared in recent years, with flowers in novel colors and bicolored combinations.
False indigos perform best on sunny sites, though they also tolerate partial shade. They are taprooted and difficult to transplant: container-grown specimens are easier to establish in the garden than bare-root stock. However, their long taproots equip baptisias to reach deeper than many plants, making them exceptionally drought tolerant. Shear and shape the plants after flowering (unless saving the seed pods) to encourage compact growth and eliminate the need for staking. Seldom attacked by pests and diseases; resistant to deer.
Baptisias are attractive in beds and borders as single specimens or in groups of several plants. The larger types can be imposing and are useful for adding structure to perennial or mixed plantings, or even planted among low shrubs. Their season of bloom coincides with Siberian irises and peonies, both of which make fine companions. A blue-flowered baptisia energizes a predominantly yellow planting; the blue-green foliage common to many harmonizes nicely with silver-foliaged artemisias and lavenders. These tough plants work well in prairie plantings, native gardens, and meadows, and their combination of striking flowers and handsome foliage makes them useful additions to cottage gardens. Baptisias attract buterflies. If left unsheared, the plants produce plump black seedpods that are popular elements of dried flower arrangements.
Propagate the species by seed; scarify seed to allow water to penetrate the hard seed coat. Sow in containers to avoid transplant shock when planting out later. Propagate named cultivars by stem cuttings taken in spring while still green and soft.
Baptisia albescens
syn. B. alba
• white
• early spring to midspring
• 2–4 ft. × 2–2.5 ft.
• sun, part shade
• Z5–8
White false indigo. Southeastern United States. Multiple small, white, pea-like flowers, to 0.5 in. long, carried in numerous 12-in. spikes or racemes atop charcoal-black flower stems; these rise above a mound of clover-like, trifoliate, bluish green leaves that remain attractive for most of the season.
var. alba (syn. Baptisia pendula) reaches a height of 3–4 ft., with pendent, large, black seed pods.
var. macrophylla (syn. B. leucantha, B. lactea) has white flowers on 5- to 7-ft. stems.
Baptisia australis
• indigo blue
• mid- to late spring
• 3–4 ft. high and wide
• sun, part shade
• Z3–9
Blue false indigo. Rich woods, thickets, and stream banks from Pennsylvania, south to North Carolina and Tennessee. Upright bushes of leafy stems bear bold spires of blue pea flowers. May need support in less than full sun. Prune after bloom to shape as a shrub “wannabe,” although this forfeits the rattling, black seedpods. Excellent naturalized in meadows or used to control erosion on difficult banks.
var. minor (syn. Baptisia minor) is more compact than the species, reaching half its height and spread. It grows naturally as far west as Kansas and Texas.
Baptisia sphaerocarpa
• yellow
• mid- to late spring
• 2–3 ft. × 2–3 ft.
• sun, part shade
• Z5–8
Missouri to Oklahoma, south to Louisiana and Texas. Yellow flowers (to 0.5 in. long) in abundant 12- to 15-in. spikes borne atop yellow-green stems above a mound of blue-green foliage. Spherical seedpods to 0.75 in. ripen to tan and then brown.
‘Screamin’ Yellow’ may reach 5 ft. Bears a profuse crop of yellow flowers above mounds of yellow-tinged, green foliage. From Larry Lowman’s program.
Other Notable Cultivars
Several of these were introduced by Jim Ault at Chicago Botanic Garden and Rob Gardner at the North Carolina Botanical Garden in Chapel Hill.
‘Dutch Chocolate’ bears chocolate-purple flowers over mounded, blue-green foliage. Late spring to early summer. 2.5–3 ft. × 2 ft. Z4–9.
‘Midnight Prairieblues’ bears 24-in.-long spikes of violet-blue flowers over three to four weeks in early summer. 48 in. × 48–54 in. Z4–9.
The Prairieblues Series, from the Chicagoland Grows program, was bred especially for regions with very cold winters and hot summers, although they thrive in most parts of the country: ‘Solar Flare Prairieblues’is golden yellow. 36 in. × 36–48 in. ‘Starlite Prairieblues’ has soft blue flowers; ‘Twilite Prairieblues’has bicolored burgundy-and-lemon flowers. 5 ft. high and wide. Z4–8.
Baptisia ‘Solar Flare Prairieblues’
‘Purple Smoke’ carries black stems with smoky violet flowers in midspring. 3–4 ft. Z4–9.
Ranunculaceae
false bugbane, beesia
This outstanding genus of two species was introduced by Dan Hinkley, who brought specimens back from a Chinese plant exploration trip in the 1990s. Both have handsome evergreen foliage with rosettes of strikingly beautiful and long-lasting, heart-shaped leaves; they are welcome alternatives to the familiar run-of-the-mill groundcover plants.
False bugbanes prefer rich, organic soils, well-drained but slightly moist even during dry spells. They require little maintenance beyond removal of spent blooms. Slugs feast on the new growth but otherwise pests and diseases are seldom a problem. Reportedly, deer ignore the foliage.
Exceptional as groundcovers, false bugbanes are fine companions for woodland plants, including trilliums, hardy cyclamens, hostas, and ferns. Plant them at the feet of bugbanes for a floral echo. False bugbanes provide drama in front of ‘Hummingbird’ summersweet or other low, shade-loving shrubs, or mix with spring-blooming bulbs such as squills and winter aconites.
Propagate by dividing the rhizomes of established plants after bloom has ended, or sow seed in containers in fall and overwinter outdoors or in the refrigerator to enable seeds to break dormancy the following spring.
Beesia calthifolia
• white
• spring
• 8–10 in. × 12 in.
• part shade, shade
• Z6–8
Ginger-leaf false bugbane. Mountain meadows and open woodlands of eastern Asia. Dense, rhizomatous clumps of polished, bronzy green, cordate leaves (similar to wild ginger, Asarum) that turn dark red in winter. Leaves are accented with a network of lighter veins, edged with red, and rimmed with teeth. Short racemes of starry, white flowers rise on purple stems from late spring on.
Beesia deltophylla
• white
• early to late summer
• 10–18 in. × 24 in.
• part shade, shade
• Z6–9
False bugbane. Sichuan Province, China. Slowly expanding clumps of smooth, purple-tinted, deep green, glistening leaves. These are heart shaped, deeply veined, and with a puckered texture; the serrate margins undulate slightly. Winter foliage is edged irregularly with a wide, reddish brown band. Mature leaves may reach 10 in. across. Sparse sprays of small, white flowers rise on 20-in. stems.
Begoniaceae
hardy begonia
This large genus mostly contains plants suited to tropical and subtropical regions, and these (Rex begonias, for example) are grown usually as houseplants or as annual bedding plants (wax begonias and others) in colder areas. However, a few begonias are hardy in temperate zones and are well worth inclusion in perennial gardens. These species thrive in partly shaded positions, where their tropical-looking foliage and lovely flowers add pizzazz from midsummer on. In particular, they make excellent partners for ferns, hostas, and astilbes, as well as low, shade-loving shrubs.
The easiest method of propagation is by collecting and sowing the pea-sized bulbils that form in the leaf axils; these frequently self-sow. Propagation by seed is also possible but offspring may not resemble their parents. Otherwise, take basal or stem cuttings in spring.
Begonia grandis subsp. evansiana
syn. B. evansiana
• pink
• summer to fall
• 12–48 in. × 12–18 in.
• part shade, shade
• Z5–9
Hardy begonia. Malaysia, China, Japan. In early spring it may seem like you’ve lost this wonderful plant, but don’t despair: the new growth does not emerge until well after late spring. Thereafter, however, overwintered bulbils or tubers make rapid progress, throwing up fleshy pink stems with large angel-wing leaves that expand to 12 in. or more long and 6 in. across. The stems are somewhat brittle; the leaves are bright green with startling red veins and a red reverse.
Hardy begonias tolerate most conditions, even dry shade. In full sun keep the soil moist, as the plants are very shallow rooted. Average to rich soil amended with plenty of organic matter is ideal as long as it drains freely. Be alert for slug and snail damage, especially when foliage is young. Attractive pink flowers, good for cutting (harvest when just opening), are carried in nodding, 6- to 12-in. sprays above the leaves, followed by lingering triangular, deep pink seedheads. Bulbils dropping from leaf axils when ripe can create a colony in a few years’ time. Site where the foliage will be backlit by the sun for a glowing picture.
‘Alba’ has white flowers with a slight pink blush. The angel-wing foliage is light green with no hint of red. Not as robust a grower as the species, but it brightens up dark places beautifully.
‘Heronswood Pirouette’ is more compact than the species but with longer sprays of hot-pink and lavender-pink flowers. 18 in. Z6–10.
Begonia grandis subsp. evansiana ‘Heronswood Pirouette’
‘Wildwood Purity’ is worth seeking. It has deep red undersides to the leaves in dramatic contrast to the pure white flowers, offset with red seedpods.
Iridaceae
blackberry lily, leopard lily
By no means rare, these iris lookalikes are nevertheless too often neglected by gardeners. Blackberry lilies are reliable, generally trouble-free plants that contribute a steady supply of showy flowers to summer borders. They have many of the virtues of their iris relatives: hardy over a wide range of climates, blackberry lilies flourish in any average, well-drained soil, and are notably drought resistant once established.
The leaves, blade-like, flat, and borne in fans, are very similar to those of bearded iris; the roots are rhizomatous, creeping outward so that the plants form slowly increasing clumps. The flowers, composed of six petal-like perianth segments (sepals and petals are not delineated), are borne in branching sprays. The blooms are followed by beige, pear-shaped pods that in late summer split open to reveal blackberry-like clusters of shiny black fruits. These fruiting stems make interesting additions to dried flower arrangements. Blackberry lilies furnish an energizing contrast to purple or blue flowers such as purple coneflowers or early-blooming asters, and harmonize well with other hot-colored blossoms such as blanket flowers and daylilies.
Iris borers can be a problem, tunneling into and destroying the rhizomes. Destroy affected rhizomes and dress wounds with powdered sulfur. Propagation is by division of the rhizomes or by seed, which requires four to six weeks of moist chilling to germinate. On hospitable sites, blackberry lilies self-seed sparingly.
Belamcanda chinensis
• orange
• mid- to late summer
• 24–36 in. × 9–24 in.
• sun
• Z5–10
Blackberry lily, leopard flower. Central Asia to India, China, and Japan. The 1.5- to 2-in. flowers are tawny and freckled with red spots. Sword-shaped leaves may reach 8 in. long. Though drought tolerant, regular irrigation during dry spells promotes more abundant bloom and growth. Not a long-lived perennial, but commonly blooms in its first year when started from seed.
‘Freckle Face’ bears 2-in., golden-apricot flowers flecked with tiny spots of deeper orange-red.
Belamcanda chinensis
Belamcanda flabellata
• yellow
• mid- to late summer
• 1.5–2 ft. × 1.5 ft.
• part shade
• Z5–10
Dwarf yellow blackberry lily. Asia. More compact than Belamcanda chinensis, this species is also more tolerant of shade and moist soils. Bears lemon-yellow flowers.
‘Hello Yellow’ has butter-yellow flowers; often listed as a cultivar of B. chinensis.
Bergenia
Saxifragaceae
heart-leaved bergenia, pigsqueak
A well-grown ground cover of bergenias is handsome indeed, though it can become shabby if neglected. These clumping perennials from rocky moors and meadows of Asia have large leaves like ping-pong paddles, often heart shaped at the base. Some are evergreen, and many of these turn red, purple, or bronze in cold weather. Clusters of pink, red, or white flowers, bell or funnel shaped, are borne atop thick succulent stems, sometimes pink tinged, branched or not.
Deadhead regularly to extend bloom time, and remove shabby foliage to the base as necessary. Foliage and flower buds of some are frost tender; flower buds brown and do not open, and leaves become black-brown and unsightly. This is not as prevalent where snow cover is reliable; elsewhere protect from searing winds and frost with a winter mulch applied in late fall.
In spite of the common recommendation to grow bergenias in shade, in temperate climes they do better in full sun. Part shade is also fine, but avoid deep shade. In general, bergenias are not well adapted to hot regions, and if attempted there they must be protected from midday sun. Soil should be average, deep, moist, and enriched with well-rotted compost or manure. Heavy clay that waterlogs easily is not satisfactory; amend with organic matter to improve drainage. Resistant to deer and rabbits, but protect from slugs, which otherwise promote that shabby appearance.
Mass bergenias as a groundcover along with meadowsweets, foxgloves, and Siberian iris to create contrasts in height and foliage texture. Planted as a skirt beneath white-barked birches or red-stemmed dogwoods, they can create a memorable winter-garden tableau. Use as edging plants along pathways or to delimit flowerbeds. British garden designer Gertrude Jekyll edged many a small bed with bergenias, often accompanied by our delicate native white wood asters (Eurybia divaricata) that tumbled over the cabbage-like leaves. Other appropriate companions include columbines, lungworts, and ferns.
Propagate by division in spring or fall. Otherwise, at the end of the growing season take 3-in. cuttings of the rhizomatous stems, making sure to include a bud. Propagate species by seed.
Bergenia ciliata
syn. B. ligulata
• white, pink
• early spring
• 6–12 in. × 12–24 in.
• part shade
• Z5–8
Winter begonia, frilly bergenia, winter bergenia. Nepal. Grown mainly for its hairy, deciduous, rounded, wavy-edged, bright green leaves that may reach 12 in. across. Clumping, spreads slowly by rhizomes. Clusters of rose-flushed white or pink flowers.
Bergenia cordifolia
• pink
• early spring
• 12–24 in. × 24–30 in.
• sun, part shade
• Z3–8
Heart-leaved bergenia, pigsqueak, winter begonia. Central Asia. Creeping rhizomes give rise to shiny, thick, cabbagey leaves, heart shaped at the base, about 12 in. long. These may turn purple and bronze as temperatures fall; some cultivars display better winter color than others. Evergreen or nearly so, in all but the coldest places. Tight clusters of deep pink flowers with rosy centers and calyces top branched pink stems.
‘Purpurea’ (syn. Bergenia purpurea) has bright purple-red flowers on red, 20-in. stems. Purple winter foliage.
‘Rotblum’ has red flowers and deep red winter foliage. 18 in.
Other Notable Cultivars
‘Baby Doll’ has maroon winter foliage color that contrasts well with the early spring clusters of pale pink flowers; these mature to hot pink over several weeks. Protect from intense sun. A heavy protective mulch in winter is beneficial. 8–10 in. Z6–8.
‘Bressingham Ruby’, a hybrid, is valued for its tolerance of dry shade. Large, cabbagey, dark green leaves become polished burgundy in cold weather. Clusters of rosy flowers above the leaves in spring. A great groundcover. 12–16 in. Z4–10.
Bergenia ‘Bressingham Ruby’
Close-up of Bergenia ‘Bressingham Ruby’ flowers
‘Cabernet’. Large, deep green leaves emerge early, closely followed by the bud clusters carried on pink stems, which open to deep pink bells. Bloom continues through late spring. Fall foliage turns deep red when temperatures drop. Semi-evergreen in zone 6 and warmer. 10–12 in. tall.
‘Eroica’. A superior long-blooming selection, displays clusters of bright purple flowers held well above wine-flushed leaves. Requires moist soil. Considered by some to be an improvement on better-known ‘Abendglocken’. 12–14 in. Z4–8.
‘Herbstblute’ (fall pigsqueak) tolerates heat and humidity well. Low basal rosettes of 6-in., rounded, dark green leaves. Light pink flowers in spring, and occasionally through the season. 6 in. Z2–7.
‘Overture’ makes tight mounds of lustrous dark foliage, purple in fall. Clusters of dramatic fuchsia flowers open in midspring on fleshy stems above the leaves. Stunning when planted in drifts or massed in semi-shade.
‘Winterglow’ (‘Winterglut’) has leathery, heart-shaped foliage with good substance. Fall color is ruby red. Clusters of deep pink flowers in spring, often with repeat bloom in fall. 12–15 in. Z3–8.
Berlandiera
Asteraceae
chocolate daisy
Sure to appeal to any gardener with a sweet tooth, this intriguing southwestern US native bears night-blooming, yellow daisy flowers that emit a fragrance of chocolate, most powerfully in early morning. Chocolate daisies thrive in full sun, tolerate drought well, and handle most soil types that drain freely. Avoid overwatering and fertilize sparingly, if at all. Add lime if soil is strongly acid.
Encourage a prolonged period of bloom by regular deadheading to the base of the individual flowerhead stem; cut plants back to the foliage mass after flowering is finished unless you are saving seed for yourself or as food for wildlife. Cut overly tall plants to ground level in midsummer. Otherwise, stake tall species or grow them among strong-stemmed perennials such as yarrows and goldenrods, or let them lollygag on sturdier neighbors; low shrubby bluebeards or silver-leaved Russian sage work well for this. Plant in drifts or patches for the strongest visual and olfactory impact. Excellent in fragrance gardens and wild or native plant gardens, as well as for edgings or grouped in flower borders. Seldom bothered by pests and diseases, and largely ignored by deer.
Propagate by direct seeding in spring after the danger of hard frost has passed, by tip cuttings in spring, or by division in spring or fall.
Berlandiera lyrata
• yellow
• summer to fall
• 12–36 in. × 12–24 in.
• sun
• Z4–9
Chocolate daisy, chocolate flower, green eyes. Open fields and grasslands of the southwestern United States and Mexico. Chocolate daisy makes loose clumps of grayish green, fiddle-shaped foliage. Light yellow daisies 1–2 in. across are accented with a central brown disk and chocolate-colored stamens. The reverse of the ray flowers (petals) is striped in red. The flowers close during the day, opening toward evening. After the ray flowers drop, a green cup (hence “green eyes”) composed of multiple calyces remains. When dry it turns tan and the seeds drop. Excellent cut flower, both fresh and dry, and in containers.
Berlandiera lyrata
Bletilla
Orchidaceae
hardy ground orchid
The exotic beauty of orchids with none of the fuss—that’s what the genus Bletilla offers gardeners in temperate regions of North America. Indeed, though they are natives of eastern Asia, hardy ground orchids take to garden cultivation much more easily than most North American species. In hospitable settings, individual bletillas expand into large, floriferous clumps, and have even been known to naturalize in Florida. Fortunately, they have shown no invasive tendencies.
Bletillas are ground dwelling; they grow from corm-like pseudobulbs that root right into the soil. Each pseudobulb sprouts several pleated leaves to 16 in. long in spring. Before the new growth has matured, a flower shoot emerges bearing a raceme of blossoms reminiscent of smaller versions of the cattleya orchid you wore to the senior prom. Healthy, established plants bear a number of such flowering shoots that continue to bloom for up to ten weeks.
Organic-rich, well-drained but evenly moist soil is essential; bletillas are winter hardy through zone 5, but won’t tolerate a combination of cold and waterlogging. In cool, northern coastal gardens, full sun is fine; elsewhere, a lightly shaded site with dappled light (a woodland edge or tall meadow, for example) is ideal; a partly shaded border or container is also suitable. These plants are shallow rooted, so avoid cultivating around their bases. In zones 5 and 6, tuck bletillas in with 2 in. of straw or other loose organic mulch after the first hard fall freeze to insulate the roots and moderate midwinter temperature swings. Winter warm spells may induce the plants to emerge prematurely; provide more protective covering if a sudden frost should occur. They force readily indoors for early spring color.
Fertilize sparingly; apply a light dose of a balanced fertilizer in early spring only, none at all during first year after planting.
Good companions for hardy ground orchids include hostas, low ferns, hellebores, and other woodlanders. Bletillas bloom best when crowded, but the pseudobulbs of mature clumps may be divided in early spring to increase stock.
Bletilla ochracea
• yellow
• late spring to early summer
• 12 in. × 6–12 in.
• sun, part shade
• Z7–10
Yellow bletilla. Grasslands of China’s Sichuan and Yunnan provinces. This species is slower growing and less robust than some others in the genus. Favors a moist, rich soil and morning sun, or light, filtered shade. Each flower stalk bears three to five pale yellow flowers sporting a purple, orange, and yellow-flecked lip.
Chinese Butterfly seed strain is reported to be extra vigorous. Introduced by Linda Guy. 18–24 in. Z6–9.
Bletilla striata
syn. B. hyacinthina
• purple
• mid- to late spring
• 1–1.5 ft. × 6–12 in.
• sun, part shade
• Z5–9
Hyacinth bletilla. China, Japan, Burma, and Tibet. This species has 1-in.-wide, pleated leaves that grow to 10 in. long; it bears pinkish purple flowers (to 1.5 in. long) in three- to seven-flowered racemes that reach 18 in. long. Withstands temporary drought. On a hospitable site, it may form a clump 2 ft. across in five years.
‘Alba Variegata’ has white-edged leaves and white flowers.
‘Albostriata’ has leaves edged with white, bright purple blooms.
‘Big Bob’ produces 2- to 3-ft. stalks with up to 20 blooms each. These are rose-lavender accented with purple and white.
‘First Kiss’ has white-edged leaves and white flowers with a purple blush on the lip.
‘Soryu’ bears mauve-blue flowers with a darker mauve-blue lip.
‘Kate’ (Bletilla striata × B. formosana) bears 40-in.-long flower spikes with up to 35 lavender flowers on each. Z6–9.
Boltonia
Asteraceae
white doll’s daisy, false aster
Excellent perennials for sunny, late-season gardens, boltonias flower when there is often little else in bloom. Bearing pink, lavender, or white aster-like flowers on tall branching stems, these natives are ideal for the back of the border, as well as in meadows, wildlife gardens, and in native plant gardens where butterflies flock to the blooms. The plants increase slowly by underground stems and naturalize if left alone.
Best sited in full sun, boltonias prefer soil of average fertility that drains well. In dry soils, growth is reduced and fewer flowers result, whereas in overly rich, moist soils and in part shade, growth is likely to be soft and lush, requiring staking. To promote shorter, stockier growth and heavier bloom, pinch out the tips of the stems periodically until midsummer. Deer resistant; may be susceptible to various foliage fungal problems.
Divide in early spring or start from seed (with protection where winters are very cold) in fall.
Boltonia asteroides
• white
• late summer to fall
• 24–60 in. × 18–36 in.
• sun, part shade
• Z3–9
White doll’s daisy, false aster, false chamomile. Poorly drained meadows and marshes, wet thickets, and ditches of the eastern and midwestern United States. Upright plants with branching stems clothed with slender, blue-green leaves. Bears masses of 0.75- to 1-in., yellow-eyed, white daisies. Growth may get a little weedy, so false asters do best in informal settings such as meadows and native plant gardens, though cultivars are sufficiently refined for flowerbeds and borders. A great cut flower.
‘Nana’, a selection of var. latisquama, blooms in early to midfall with lavender-pink flowers. 36 in. × 24 in.
‘Pink Beauty’ (syn. Boltonia rosea), beloved of butterflies, bears abundant soft pink flowers. Has a more open, lax habit than ‘Snowbank’. 4–5 ft. tall.
‘Snowbank’ is tough and more disease resistant than other cultivars. Bluish green foliage topped with clouds of white daisies on stems to at least 48 in. Plants may spread to 48 in., so allow plenty of space. For stronger stems and less height, cut back by about a third by midsummer. Mixes well with tender sages including Mexican sage, pitcher sage, and anise sage, and makes a statement backed with dark-foliaged shrubs.
Boltonia asteroides ‘Snowbank’
Brunnera
Boraginaceae
perennial forget-me-not
This genus contributes one species with a number of notable selections to the garden. Since the foliage remains attractive throughout the growing season, plants are effective in flowerbeds as specimens or grouped as a foil for colorful summer perennials and annuals. Variegated cultivars—ideal for containers in light shade—are especially susceptible to leaf burn when exposed to intense sun.
Provide moisture-retaining fertile soil for best results; the leaf edges tend to crisp if allowed to dry out, especially where temperatures are higher. Brunneras contrast well with spring bulbs, including daffodils, grape hyacinths, and summer snowflakes. Barrenworts, lungworts, and ferns are good companions in light shade, massed under trees and shrubs, or in drifts. Deer resistant, but protect from slug damage. Pests and diseases are seldom serious. Foliage of variegated forms may revert to all green; remove such reversions at their base.
This low-maintenance perennial self-seeds freely, but propagate selections vegetatively by division in spring. Increase the species by root cuttings in winter.
syn. Anchusa myosotidiflora
• blue
• late spring to early summer
• 1–2 ft. × 18 in.
• sun, part shade
• Z9–3, HS
Siberian bugloss, heart-leaved brunnera, perennial forget-me-not. Moist, open woodlands from eastern Europe to western Siberia. Rough-textured foliage held aloft on long petioles rises from the crown to form handsome clumps that mature after the plants bloom; young leaves expand into heart-shaped blades 6–8 in. across. The 0.25-in., yellow-eyed, blue flowers are carried in loose, terminal panicles atop slender, hairy stems.
‘Dawson’s White’ has irregular cream margins to its leaves. Similar to ‘Variegata’ but reputed to be less susceptible to sunburn. Foliage may revert. To 18 in.
‘Emerald Mist’ bears mid-green leaves widely blotched with silver toward the edges. 18 in. tall.
‘Hadspen Cream’ has leaves irregularly bordered with cream. 12–15 in.
‘Jack Frost’ has predominantly silver leaves etched with emerald veins below blue flowers. ‘Mr Morse’ is similar but white flowered. 15–18 in.
Brunnera macrophylla ‘Jack Frost’ makes a charming skirt for weigela flowers
‘Langtrees’ (‘Aluminum Spot’) sports pairs of large, silver ditto marks around the leaves. To 12 in.
‘Looking Glass’, a sport from ‘Jack Frost’, has more silvery leaves and less green veining. Not as hardy as other cultivars. 6–15 in.
Bulbinella
Asphodelaceae
Maori onion
Hailing from the grasslands of South Africa and New Zealand, Maori onions are likely to suffer frost damage in cold regions. However, they thrive in warmer, less humid areas, especially on the West Coast; where they can’t overwinter outdoors safely, cultivate in pots and set outside in summer.
Maori onions have fleshy roots, from which sprout basal rosettes of glossy, grassy leaves. From late winter on toward summer, sturdy scapes rise from the foliage rosettes, bearing cone-shaped clusters of starry flowers at their tips; flowers may be yellow, orange, white, or pale pink. After flowering, the plants undergo a period of summer dormancy, and though Maori onions benefit from regular watering during their growing season, they should be kept dry during dormancy. When the plants retreat underground is also the best time to snip off the dead, grass-like debris that accumulates around the base. Excellent for cut flowers.
The species described here is the most commonly available, but specialist growers offer other species, too. Pests and diseases are insignificant; may be browsed by deer.
Propagate by seed as soon as it ripens, or divide in autumn.
syn. Anthericum hookeri, Chrysobactron hookeri
• yellow
• late spring to early summer
• 1.5–3 ft. × 1–3 ft.
• sun, part shade
• Z8–9
Maori onion. New Zealand. This clumping perennial has succulent, grass-like leaves, 2 ft. long, with a longitudinal channel. They arch outward giving a vase-like effect. Strong scapes rise above each clump, topped with tight spikes of bright yellow, starry flowers tipped with a cone of green buds. Excellent beside ponds or in damp rock gardens, where they will not dry out during the growing season. Outside their range of hardiness, Maori onions provide good material for containers overwintered in a sunroom or porch, and put outdoors in summer.
Buphthalmum
Asteraceae
yellow oxeye daisy
A perky yellow daisy distinguished by its long bloom time and its excellence as a cut flower. This hardy, widely adapted genus flourishes even in poor, damp soils where so many other perennials fail. Rich soil causes soft growth that must be staked. Prefers sweet soils.
Pests and diseases are usually insignificant; seldom browsed by deer or rabbits.
Propagate by division prior to bloom time in spring or immediately afterward. Seed germinates readily in spring or fall.
Buphthalmum salicifolium
• yellow
• late summer to fall
• 1–2 ft. × 2 ft.
• sun
• Z5–8
Willowleaf oxeye, dwarf sunwheel. Central Europe. Slender, upright stems clothed with alternate, narrow, toothed, willow-like leaves to 4 in. long. Blooms are solitary and bright yellow, 2–3 in. wide, with a darker yellow disk; the ray flowers are squared off at the tips. Flowers open over a period of several weeks. Partners well with blue sage, Russian sage, and bluebeard, and also makes a fine show in meadows or wild gardens, especially when intermingled with mountain mint and grasses.
‘Alpengold’ has 2-in.-wide, golden flowers. 20 in. Z3–9.
Buphthalmum salicifolium ‘Alpengold’
‘Dora’ carries the yellow flowerheads atop dark purple stems. 24–30 in.
