When August melts into September, nights are suddenly noticeably longer, while flowering perennials seem to grow wilder, to compensate. One of the greatest gardening pleasures of this cusp-season is the effusion of a tousled collection of native plants whose flowers are the languid counterpoint to spring’s cheerful bursts of blossoms. If we must have winter, then these sultry blooms are a fitting way to celebrate the dying of the light. Here are 11 native perennials for late summer and fall.
Photography by Marie Viljoen.
Agastache, anise hyssop (Agastache foeniculum)
Of all the native perennials that bloom late into the year, if I had to choose just one to provide summer-to-fall flowers, it would be Agastache foeniculum and its various cultivars. Tall in stature, with licorice or mint-scented leaves, and profuse little blue flowers, these sun-loving hyssops provide height and bulk and filler, all at the same time. They are also elegantly lanky, and are a day-long buffet for bees, other pollinators, and even hummingbirds. If you can bear it, grit your teeth and cut the waning flowers back in late summer for a late fall resurgence; and leave those flowers to set seed for seed-eating birds like goldfinches.
Asters (Symphyotrichum pilosum, S. ericoides, and others)
No late summer garden seems complete without asters—low-maintenance and long-blooming. Heath aster (Symphyotrichum ericoides, above) likes full sun and is hardy from zones 3 to 10. Hairy aster (S. pilosum) can handle more shade and likes moist soil. It is hardy from zones 4 to 8. For woodland gardens, choose wood aster (Eurybia divaricata).
Flowering spurge (Euphorbia corollata)
Clump-forming flowering spurge is one of the native perennials that seems to fly under the horticultural radar. Also known as the baby’s breath of the prairie, it has a loose, breezy habit with wiry stems tipped by flower-like bracts and distinctive, three-celled seed capsules. Flowering spurge pairs well with grasses and golden rods, asters, helianthus, and partridge pea. It flourishes in full sun and is hardy from USDA zones 4 to 9.
Great burnet (Sanguisorba officinalis)
Great burnet is potentially statuesque, but it never dominates, visually. Instead, its threadlike stems hold burgundy flowerheads effortlessly aloft, adding tousled lightness to late summer and autumn gardens. Grow great burnet in full sun, and enjoy its cucumber-flavored leaves in salad. It is hardy from zones 4 to 8.
Ironweed (Vernonia fasciculata and other species)
The vivid amethyst tufts of ironweed are welcome relief from the cheery but often dominant yellow palette of the late summer native garden. Smooth ironweed (Vernonia fasciculata) is hardy from zones 4 to 9 and flowers best in full sun. Giant ironweed (V. angustifolia) grows better in partial shade, and is hardy from zones 5 to 8. Both species require ample moisture.