After the excitement of spring and summer flowers, many gardeners look over their dull September flowerbeds in dismay. There are many fall-blooming plants, however, that add pizazz to the fall garden. Chrysanthemums rank high on the fall-blooming flower list, but other showy flowers deserve a moment in the autumn sun.
Many spring-blooming annuals catch their second wind when the temperatures drop. Violas, petunias and lobelia, usually considered spring flowers, have flushes of blossoms in the fall. The yellows, golds and oranges of marigolds contrast with the purples and blues of pansies. Trim spring-planted snapdragons (Antirrhinum sp.) down after their early-season bloom, and the plants produce tall spires in fall. English daisies (Bellis perennis) have cheerful, rosy pink or white fringed blossoms on tidy, 6-inch-tall plants. The Houston Chronicle recommends Drummond phlox (Phlox drummondii), a border plant covered in small, five-petaled flowers and available in blue, red, rose and white.
Asters (Aster sp.) start their floral show in late summer and continue through September, often blooming into October. New York aster (Aster novi-belgii) grows in 3-foot-tall mounds. For deep pink, semi-double flowers plant 'Ernest Ballard.' The showy 'Winston Churchill' has red flowers. Often considered a New York aster, A. x dumosus is a shorter, low-growing cultivar that grows only 12 to 15 inches tall. 'Jenny' has red flowers, while 'Professor Anton Kippenberg' has cheerful blue, semi-double blooms. For a colorful garden, plant asters with sunflowers and goldenrod. Asters grow in USDA zones 4 to 9.
Helenium (Helenium autumnale) has all the classic September colors. The coneflower-shaped blooms dress the garden in rich shades of orange, warm red and sunflower yellow and complement cooler blue flowers like salvias. Plant helenium at the back of the border, as these perennials grow 3 to 5 feet tall and 2 to 3 feet wide. 'Moerheim Beauty' has red flowers with tones of brown, and 'Bruno' has a bronze cast. "Perennials for Every Purpose" states that helenium earned its common name, sneezeweed, as a Native American remedy for hay fever. Allergy sufferers shouldn't hesitate to plant sneezeweed for weeks of fall color. Helenium grows in USDA zones 3 to 9.
Often overlooked, fall-blooming bulbs like autumn crocus (Colchicum sp.) add a textured contrast to the pincushions of mums and asters. Like other members of the lily family, colchicums produce foliage in the spring. However, the strap-like leaves die back in summer, and the crocus-shaped flowers appear in the fall. Colchicums bloom in shades of white, pink and lavender. The double flowers of the violet colchicum 'Waterlily' produce up to 20 petals, according to Iowa State University, and colchicums are hardy to USDA Zone 5.
For a true crocus, plant showy crocus (Crocus speciosus). A shorter plant, reaching only 6 inches tall, showy crocus dresses up walkways, borders and the front of the garden. The late-September flowers are violet blue with yellow and orange interiors, and showy crocus is hardy in all zones, but prefers winter chill. 'Conqueror' is a dark blue, while 'Cassiope' has sky-blue flowers.