When fall arrives, the days become cool and the sun, being lower in the sky, throws a vivid spotlight on trees and their changing cloaks of color. Autumn’s shorter days also trigger certain late-blooming perennials to open their flowers and delight us. They have quietly been growing through the summer and now, when other perennial flowers start to go dormant, chrysanthemums, anemones, asters, dahlias, and toad lily cheerfully celebrate the brilliance of fall. They are prime candidates for an end-of-the-growing-season flower garden. You can revel in the crisp air and clear blue skies, knowing that autumn is, as the 19th-century American poet William Cullen Bryant described, “the year’s last loveliest smile.”
A Fall Flower Delight garden is a sweet way to exult in the quiet moments of autumn. Find a sunny spot that you can view from a warm house and make a wide plant bed. Amend the soil amply with compost. Go beyond the standard autumn palette of deep red and bright yellow chrysanthemums and include lavender asters, pink dahlias, sedum ‘Autumn Joy,’ and vivid white Montauk daisies. In spring, plant annuals such as the apricot-hued ‘Unbelievable Lucky Strike’ begonia and the orange ‘Luscious Marmalade’ lantana among the nascent fall-blooming perennials. The warm-toned annuals will bloom all summer and will be ready for some companionship when the asters, dahlias, and others finally open up.
A striking fall flower, an annual in cooler climes, is the showy Mexican bush sage (Salvia leucantha) that blooms purple, white, or bicolor on tubular flower spikes that rise above the foliage. This bushy subshrub flowers from late summer to frost, grows 2 to 3 feet tall, and adds a vertical accent to any fall garden. It is best in full sun and is suitable for USDA hardiness zones 8–10. Plant this along with the thread-leaf bluestar (Amsonia hubrichtii), a three-season perennial performer that features clusters of sky-blue flowers in late spring and finely textured bright green foliage that turns a rich yellow in the fall. The thread-leaf bluestar was named the 2011 Perennial Plant of the Year by the Perennial Plant Association (PPA).
The soft pink, slightly cup-shaped flowers of Japanese windflower (Anemone × hybrida ‘Robustissima’) float in the breeze 3 to 4 feet above mounded foliage in late summer through October. This windflower is a star in a fall flower garden, blooming for weeks. A vigorous perennial, ‘Robustissima’ windflowers like evenly moist, well-drained soils in sun to part shade. Beware—they live up to their “robust” name and may naturalize in the garden by spreading rhizomes to form large colonies. They are easy to grow and are deer and rabbit resistant. May need extra winter mulch in colder areas. Zones 4–7.
Chrysanthemums, or mums as they are often called, are a fall favorite because of their amazing range of colors and bloom types. They respond to shorter daylight hours for flowering and are at their zenith between August and October. They like moist, well-drained soil in full sun. Cut stems back with a pair of sharp pruners from late spring to midsummer (Memorial Day to July 4) to encourage compact, bushy growth. After they flower, cut these perennials back to 8 inches high and mulch in winter. Mums are somewhat resistant to deer and rabbits. Zones 5–9.
‘Hillside Sheffield Pink’ chrysanthemum (Chrysanthemum rubellum ‘Hillside Sheffield Pink’) is a vintage mainstay of the fall garden. It is a clump-forming perennial that starts out with medium pink buds in early fall that open into gorgeous single daisy-like apricot-pink flowers with yellow centers in October. It grows 24 inches tall and 36 inches wide, and it is a vigorous addition to any flower garden. ‘Hillside Sheffield Pink’ tolerates heat and drought, and it is perfect for a sunny rock garden, as shown here. Pinch back hard in early June to keep plants compact. Long, blooming flowers are attractive to butterflies. This is at the Steinhardt Garden in Mount Kisco, New York. You can visit this garden through the Open Days program of The Garden Conservancy (www.gardenconservancy.org/open-days). Zones 4–7.
The native perennial bluestar (Amsonia hubrichtii) was discovered growing in the wild in the early 1940s. It is native to south-central United States. It is a great filler in the flower garden—easily grown in average, medium, well-drained soil in full sun to part shade. It has powdery blue star-like flowers in late spring. Its best fall foliage color occurs in full sun. Cut back stems by 6 inches after flowering to keep plants as a neat foliage mound. Zones 5–8.
There are more than 4,000 bee species in the United States, but they are in peril due to our overuse of pesticides and herbicides. Bee-friendly gardens, with blue salvia as shown here, are a way we can help Nature restore balance. Plant flowers and native wildflowers that provide loads of nectar to help our endangered bees. Bees are able to smell and detect nectar with a high concentration of sugar, so they will find them. Bees can see white, yellow, blue, and even UV colors. Bees cannot see red.
If there is one flower to plant in a bee garden, this is it! The silvery mountain mint (Pycnanthemum muticum) is a native perennial that is one of the best nectar sources for bees and native butterflies. It is a 3-foot-tall plant with densely packed, small tubular pink flowers with underlying showy, leaflike silver bracts. It naturalizes and spreads by rhizomes, so it may need to be divided after a few years. Mountain mint is loaded with pulegone, a clear, oily liquid that acts as a mosquito repellent when rubbed on the skin! Zones 4–8.
Here, a bee forages on the tubular, lavender-blue flowers of ‘Blue Fortune’ anise hyssop (Agastache ‘Blue Fortune’). Bees, butterflies, and hummingbirds love the bottlebrush-like flowers, which are filled with nectar. This licorice-scented perennial thrives in sun and dry soils, and they are perfect for an herb garden or mixed border. Grows 2 to 3 feet tall and is hardy in zones 4–9. According to The Honeybee Conservancy (www.thehoneybeeconservancy.org), bees are a wonderful way for children to learn about ecology, agriculture, and mutual cooperation.