Sunny and Reliable
Black-eyed susan (Rudbeckia) is a vigorous perennial that blooms prolifically from late summer to frost. It tends to naturalize, and it also doesn't need much deadheading. USDA Zones 3 to 8
Exceptionally Drought Tolerant
Sedums include a broad class of fleshy-leaved perennials that vary in height, color, time and color of bloom. 'Autumn Joy' sedum, shown here, produces its broccoli-like flowers in late summer, and they gradually become bronzy red as fall approaches.
Native to the western U.S., blanket flower (Gaillardia x grandiflora) flourishes in hot sun, providing dazzling color to the garden when a lot of other plants wilt in the heat. In some parts of the country, blanket flower is a short-lived perennial and is treated as an annual, but it self sows.
Yellow Focal Point
A dramatic plant for the garden in late summer and fall, the swamp sunflower produces bright yellow flowers on 6- to 10-foot plants. Prefers wet soil but can handle dryer conditions if hand watered occasionally. USDA 6 to 9.
Plumbago, aka leadwort, comes into its own in late summer when blue flowers appear on its carpet of foliage. Then in fall, the leaves turn russet red. This deciduous groundcover tolerates full sun to light shade; where summers are hot, give it light afternoon. USDA Zones 5 to 8.
A common sight in fall meadows, joepye weed (Eupatorium purpureum) attracts butterflies and bees. (Image courtesy of Reiman Gardens)
Many salvias bloom in fall. Here, Salvia leucantha) creates a dramatic four- to five-foot-tall wash of color.