By autumn, many of the spring- and summer-blooming perennials have faded, leaving the garden bleak and colorless. But some perennials, such as asters and goldenrod, will provide vivid color until the first killing frost or even later. If you decide to plant now, remember, the earlier the better, as the roots will benefit by giving them some time to get established before the ground freezes.
Here are some fall-blooming perennials
that will add color to your landscape
Asters (Aster spp.)
Hardy asters are a mainstay of fall gardens in northern New England. They are available in a variety of colors from white and pink to lavender, purple, and blue, and in heights from a foot to four feet tall. Asters prefer a sunny location and do best in a site with well-drained soil. The New England aster (Aster novae-angliae), one of the showiest of the fall-flowering asters, blooms from August to October. It has lavender, white, red, pink, or purple flowers and grows four- to six-feet tall with a three to five -foot spread. 'Purple Dome' is a popular lower-growing cultivar, only reaching about two feet high.
Boltonia (Boltonia spp.)
A close relative of the aster, Boltonia is also known as the "thousand flowered aster" because it produces many half-inch flowers on silvery, blue-green foliage, beginning in September. Use this plant, which grows from three to five feet tall depending on variety, in a meadow garden or at the back of a perennial bed. It likes moist, fertile soil and lots of sun. A popular variety is white Boltonia (Boltonia asteroides), which produces masses of white or pale purple flowers with a yellow center.
Goldenrod (Solidago spp.)
Don't confuse goldenrod with ragweed. Although both bloom at the same time, it is the ragweed that is to blame for hay fever attacks, not goldenrod. This perennial has a plume-like bloom, consisting of many tiny clusters of yellow and golden-yellow flowers. It grows well in poor to average soil with good drainage in a site that gets at least six to eight hours of sun a day. The showy goldenrod (Solidago speciosa), a good variety for New England gardens, has soft yellow flowers on stalks from two to six feet high. If you want something different, try the low two-foot cultivars 'Golden Fleece' or 'Fireworks.'
Helenium (Helenium autumnale)
This is also referred to as Helen's flower, false sunflower, or sneezeweed. It is a prolific plant with many branched stems and numerous daisy-like flowers with raised, button-like centers. Colors range from gold and orange to bronze and maroon with dark centers. Helenium grows to three to four feet tall when grown in full sun and will produce flowers from late summer through fall. It likes plenty of moisture to bloom best, but well-drained soil. Most may need staking, but a newer low cultivar 'Coppelia' usually doesn't.
Joe pye weed (Eupatorium)
This perennial with its eight-inch dusky pink and purplish flower heads and leathery green leaves is an excellent plant to grow to attract butterflies to the garden. Although it prefers moist soil and sun (even tolerating wet soils as by a pond or stream), it will tolerate drier soils and light shade. Because it can reach heights of six feet, it's best planted in the back of the garden. 'Gateway' is one of the better cultivars to grow.
Rudbeckia (Rudbeckia spp.)
A favorite of many gardeners, rudbeckia or coneflower produces rich yellow-gold flowers with dark brown, black, or green cone-shaped centers and drooping petals. This perennial flourishes in full sun and well-drained soil although will tolerate most soil types. Plant in masses for a vibrant visual display that will last from July until frost. Plants grow from two to nine feet tall, depending on cultivar. 'Goldsturm' is the most popular cultivar, and one of the most popular of all perennials.
Sedum (Sedum spp.)
Another name for this fleshy-leafed, succulent plant with its flat-topped flower clusters of yellow, rose, or pink flowers is stonecrop. Although various cultivars bloom at different times throughout the season, some, like the ever-popular 'Autumn Joy,' produce flowers in late summer and fall, with the blooms and leaves changing color as the season progresses. Sedums make excellent edgings for borders. Some cultivars have variegated leaves, others solid colors such as bluish or red shades.
Toad lily (Tricyrtis)
A good perennial for partial shade and moist soil is the toad lily, which has clusters of pale, orchid-like flowers covered with pink, red, or purple dots. It grows to heights of up to three feet tall and flowers from mid- to late September until frost. Flowers are showy close-up, but not from a distance, so plants should be placed where easily seen as along paths. This plant is only hardy in warmer parts of our region (generally USDA zone 5 and warmer).
You also might like to include some of the ornamental grasses to add color, shape, and texture to the fall garden. Foliage may be green, bluish-green, or silver changing to beige or brown in late fall and winter. Some varieties have variegated foliage. Most are disease- and pest-resistant, adaptable to all types of growing conditions, and don't require a lot of maintenance or frequent division as do a lot of perennials.
By Dr. Leonard Perry, Extension Professor University of Vermont