Late summer is the time when most flowers are completing their season. Arranging a long-season booming garden involves planting flowering plants with different seasonal blooms. Late summer flowers fill in the gap between fall and summer flowering plants. Many plants start flowering in late summer and continue through fall.
Summer-blooming annuals grow, blossom and perish in a single growing season. 1 example is the blue shrimp plant (Cerinthe major “Purpurascens”) with green leaves and powdery purple bracts above hanging purple blooms. This cottage garden plant falls seeds after flowering. Tickseed sunflowers (Bidens aristosa) grow to 5 feet tall creating tens of thousands of 2-inch-wide daisy-like flowers with yellow petals surrounding a dark eye. The green leaves are covered with the flowers from late summer through the fall. Remove fading blooms before seeds form to prevent self-seeding.
Most bulbs are thought to blossom in the spring, however, there are some varieties that produce their blooms in summer season. 1 late season flowering bulb is the pineapple lily (Eucomis comosa “Oakhurst”), which grows best in U.S. Department of Agriculture plant hardiness zones 8 through 11. This clump-forming bulb produces reddish-purple strap-like leaves with a foot-long purple blossom stalk at the late summer covered with six-petaled pineapple-yellow blossoms. Summer hyacinth (Galtonia candicans) rises in USDA zones 7 through 10, sending up flower spikes covered with white bell-shaped blossoms in summer season. The fragrant flowers appear 3 to 6 feet over the dark green strap-like leaves.
Late summer flowering perennials commonly remain in bloom until cold winter weather happens. Chinese astilbe (Astilbe chinensis “Pumila”) sends up late summer flower plumes 24 inches tall made up of smaller pinkish-purple blossoms. The 10-inch-tall leaves form clumps 12 to 24 inches wide in USDA plant hardiness zones 4 through 9. These perennial plants make fantastic cut flowers. Perennial toad lilies (Tricyrtis “Sinonome”) grow well in USDA zones 4 through 9 with 1-inch-wide white and purple spotted blossoms appearing at the top of 2 – to 3-foot tall stems during the summer season. When grown in partially sunny states in well-draining dirt, the clumps spread 1 to 2 feet wide.
Many different types of shrubs produce late summer blooms. Bloom-A-Thon red reblooming azalea (Rhododendron “RLH1-1P2) is in flower for about five months, blooming in the spring and then blossoming again in summer season. This tree grows as an evergreen in USDA zones 6 through 9, reaching 3 feet tall and wide with reddish-pink flowers. Blush Satin rose of Sharon (Hibiscus syriacus “Mathilde”) rises as a deciduous tree in USDA zones 5 through 8, reaching 8 to 12 feet tall and spreading 4 to 6 feet wide. Big soft pink flowers develop a reddish eye and bloom from late summer until early fall.