The Perennial Matchmaker

Sometimes, the inspiration for your combinations may come from the season, rather than specific plants or colors. Each season has its own special considerations that can help to guide your choices: the hues you use, the perennials (and other plants) that you include, and the sites where you focus your efforts.

Spring is a tricky time for planning effective and beautiful combinations because weather has a significant effect on exactly when and for how long things bloom. Flowers that last for weeks in cool conditions may be at their peak for just a few days if there’s an unseasonably warm spell. Hot, sunny days also bleach out blooms that are prettily pastel in mostly overcast conditions. Warmer-than-usual weather may significantly speed up flowering on some perennials but not others, even within the same bed, so from year to year, two plants may bloom at the same time, just overlap, or miss each other altogether. But when early-season combinations do work, you’ll know that they were well worth waiting for.

One way to improve your chances of enjoying a delightful spring show is to group your spring combinations in one part of your yard. With many early bloomers in one spot, there will always be something looking great. It’s a particularly good time to focus your attention on sites that are sunny in spring and shady later, because many shade perennials send up their flowers early in the season. For inspiration, look to your local woodlands to see what’s blooming during the spring season.

Including colorful foliage along with the flowers is yet another way to succeed with spring perennial groupings. Blue, yellow, and purplish leaves, in particular, often produce their most intense hues in their new spring growth. They provide a dependable splash of color as early flowers come and go, then still look nice later in the season. Just keep in mind that dark foliage can blend right into bare soil or mulch unless it has other leafy companions nearby to provide a lighter background.

Color-wise, white flowers are abundant in spring, as are pinks, yellows, and purple-blues, so white and pastel combinations are well suited to the season. Warm colors, such as reds, oranges, and golds, tend to be the least common at this time of year, but there are some, and a small bed of them can supply a dash of summery warmth to your view even on a chilly spring day.

Most spring-blooming perennials are quite short (knee level or lower, especially in early to mid-spring), so think about combining them with early-flowering shrubs and trees for color closer to eye level, too. Spring bulbs make excellent co-stars for perennials, contributing a wide range of flower forms and colors early in the season and then disappearing back below ground by early summer.

There’s so much going on at this time of year that it’s easiest to think of summer as two seasons: early to midsummer and mid- to late summer. The palette of perennials you’ll use in your combinations can be very different for each, but there’s some overlap, as well, because some early-summer perennials flower again later in the season and some long-flowering selections are in bloom throughout this period.

It’s no coincidence that perennial gardens tend to be heavy on late-spring and early-summer bloomers. Most of us are drawn to shopping for plants in mid- to late spring, so retailers make sure their displays are filled with perennials grown to be in bloom around that time. (Often, that means the plants have been in a greenhouse to hurry them into flower; in subsequent years, they’ll bloom a few weeks later.) This abundance gives lots of options for early-summer combinations, but when you fill your yard with only those, you won’t have much to look at later. If you’re hoping to extend your garden’s interest past the first big show, make it a point to include some combinations that feature long bloomers, rebloomers, and later-summer perennials, as well, to get a long season of beauty from your beds and borders. Also, check out “Perennial Pruning Basics” for tricks you can use to delay or extend the flowering periods of many summer favorites.

The soft colors of spring tend to extend into early summer; later on, they’re likely to bleach out unless they’re in some midday to afternoon shade. As the weather heats up, so do the hues in sunny gardens: Bright-and-bold combos, with brilliant reds, oranges, and yellows; saturated jewel tones, such as ruby red, amethyst purple, sapphire blue, and topaz yellow; sunset shades, including deep reds, golds, and oranges; and twilight colors (blues, violets, and purples with touches of magenta, pink, and yellow-orange) are equally appropriate. Mid- to late summer is an especially good time for plantings based mainly on yellows and golds, and there are lots of deep to medium pinks to choose from, as well. In shady areas, summer is a great time to play with interesting foliage color and texture groupings.

Style-wise, early summer is peak season for the traditional cottage-garden look, with classics such as bellflowers (Campanula), catmints (Nepeta), irises, lady’s mantle (Alchemilla mollis), and peonies transitioning to summer favorites such as daylilies (Hemerocallis) and summer phlox (Phlox paniculata). Mid- to late summer is a great time to take inspiration from sunny meadows and pair ornamental grasses with medium-height to tall flowering perennials, such as Joe-Pye weeds (Eupatorium), milkweeds (Asclepias), and rudbeckias (Rudbeckia).

There’s no reason that the end of summer has to mean the end of the gardening season. Early to mid-fall can be a prime time for amazing combinations, especially in sunny gardens. Besides the summer perennials that rebloom, or continue to bloom, in autumn, there are late bloomers that don’t peak or even begin to flower until then, such as many asters and goldenrods (Solidago). Seed heads and berries add intriguing shapes and colors.

One fall feature that many perennial gardeners overlook is autumn color changes in leaves. Just like deciduous shrubs and trees, quite a few perennials can produce showy fall foliage colors, including balloon flower (Platycodon grandiflorus), bluestars (Amsonia), Bowman’s roots (Gillenia), Culver’s roots (Veronicastrum), hardy geraniums (Geranium), and peonies, as well as most warm-season ornamental grasses. Combined with late bloomers in rich purples, reds, yellows, oranges, and golds, they bring the colors of autumn woodlands and roadsides right to your garden. If those colors are too bright for your taste, more muted tones—lavender, rosy pink, buttery yellow, and peach, perhaps with touches of coral and maroon as accents—are perfectly appropriate.

In mild climates, long-flowering and late-flowering perennials can continue to bloom into the winter months, possibly even overlapping with those that typically bloom in spring or even early summer in cooler regions. Elsewhere, it’s more common for perennials to have little or no presence in winter, either because they get cut down to tidy the garden in mid- to late fall or they get covered with snow for months.

That doesn’t mean that you can’t attempt to create combinations or even whole borders that are attractive through typical cold winters, though. You just need to be willing to expand your definition of beauty to include colors like tan, brown, gray, and black and to appreciate features such as dried foliage, interesting “skeletons” (dried stems), and long-lasting seed heads. Many warm-season ornamental grasses, for instance, dry beautifully as autumn progresses, turning from their bright fall colors to shades of buff, golden tan, or pale copper. And if you stop snipping off faded flowers after midsummer, you’ll enjoy the intriguingly shaped, brown to black seed heads of durable perennials such as agastaches (Agastache), bee balms (Monarda), echinaceas (Echinacea), and rudbeckias (Rudbeckia). These sorts of features look fantastic when dusted with snow or encased in ice, and they also provide welcome shelter and food for birds and beneficial insects through the winter months.

Site a winter combo or border like this where you can admire it through a window while you’re cozy indoors, and you’ll have a great view through the better part of winter. Cut down individual plants as they start to look messy, or wait a bit longer and cut down the whole planting in late winter or early spring to make room for the new growth.

There are some perennials that hold live foliage in a variety of colors through winter, including blue fescues (Festuca), Christmas and shield ferns (Polystichum acrostichoides and P. setiferum), European wild ginger (Asarum europaeum), hellebores (Helleborus), heucheras (Heuchera), lavenders (Lavandula), evergreen sedges (Carex), and yuccas (Yucca), to name a few. Grouped near a doorway, planted along a frequently used path, or combined with evergreen shrubs and groundcovers, they can provide enough interest to help you get through the winter months, then go on to earn their keep with their fresh foliage (and often flowers, too) throughout the growing season.

Marking the Seasons

Exactly when each season starts and ends depends on where you live and which definition you use. Though calendars mark the seasons by the equinoxes and solstices (around March 20 for the spring solstice, for instance, and around June 21 for the summer solstice), meteorologists in the Northern Hemisphere define winter as the 3 coldest months, summer as the 3 warmest months, and spring and fall as the periods in between. In many parts of North America, you can think of spring as March through May, summer as June through August, fall as September through November, and winter as December through February. If you live in a particularly mild area, though, your spring perennials may start in February or even earlier; in cold climates, those same flowers may not appear until mid- or late May.

All this variation means that it’s impossible to give a definitive bloom time and duration that will apply to a particular perennial wherever it grows in the country. In this book, I use the March-through-May, June-through-August, September-through-November, and December-through-February system for seasons and give general bloom times that apply best to Zones 5 through 7. In warmer areas, figure that they’ll be several weeks earlier; in areas to the north, they’ll likely be several weeks later.

MAKE THE MOST OF SPRING BULBS. Daffodils, grape hyacinths (Muscari), and other hardy bulbs do a great job filling the open space that’s often so obvious in early-season gardens, adding spots or drifts of color and then disappearing as the perennials emerge and expand.

SPREAD THE WEALTH. Don’t let your beds and borders fizzle out after midsummer. Instead, take advantage of some of the many perennials that don’t even begin flowering until hot weather arrives, such as golden lace (Patrinia scabiosifolia), Joe-Pye weeds (Eupatorium), summer phlox (Phlox paniculata), and orange coneflower (Rudbeckia fulgida).

OPTIONS FOR AUTUMN. Colorful leaves and showy seed heads are excellent complements to fall-flowering perennials. This late-season combination features the tall lavender-purple blooms of Tatarian aster (Aster tataricus) behind the coppery fall color of ‘The Blues’ little bluestem (Schizachyrium scoparium) and the dark dots of orange coneflower (Rudbeckia fulgida) seedheads.

LINGERING INTO WINTER. Many perennials that look good in late summer through fall hold their dried stems, leaves, and seed heads through much or all of winter. The image above is of the border shown on Options for Autum as it looks several months later, with the skeleton of aromatic aster (Aster oblongifolius), seedheads of purple coneflower (Echinacea purpurea), and dried plumes of ‘Dallas Blues’ switch grass (Panicum virgatum) also visible.