A combination of late-summer perennials and shrubs can add color and interest to the garden for several months. Plants that bloom in late summer often continue flowering into fall and even until the first frost. The best time to plant late summer blooming shrubs and plants is in the spring, late summer or fall, although they can be planted any time of the year if the ground is not frozen.
Spikes of purple flowers on Anise Hyssop (Agastache foeniculum) plants attract butterflies and hummingbirds from early summer to fall. The perennial plants grow 3 feet tall in full sun and moist, well-drained soil.
Butterfly bushes grow 3 to 6 feet tall and wide in full sun with well-drained soil. They have spikes of white, pink, purple, red or yellow flowers from early summer to fall that attract butterflies.
Joe Pye Weed
Clusters of tiny pink or purple flowers top the tall stems of Joe Pye weed (Eupatorium purpureum) plants from late summer to fall. The perennial plant grows 5 to 7 feet tall, and 4 feet wide. The flower heads grow up to 18 inches across.
New York Asters
New York asters (Aster novi-belgii) have daisy-like flowers in shades of pink and purple, as well as white. They bloom from late summer to fall. The perennial plants grow 1 to 5 feet tall in full sun and well-drained soil.
Rose of Sharon
Rose of Sharon (Hibiscus syriacus) shrubs have white, pink or purple hibiscus-like flowers from mid-summer to fall. They grow 10 to 15 feet tall in full sun and well-drained soil.
White, pink or red flowers seem to float on the long stems of whirling butterflies (Gaura sp.) in summer and fall. The perennial plants have an open spreading shape that grows 3 to 4 feet tall and wide.