What Flowers Bloom in September?

If you love flower gardening, your blooming season needn't end when fall arrives. Many different plants produce flowers in September -- some continue their summer flowering into fall, while others start to bloom in September. By choosing from these plants, you can enjoy garden color even after the weather turns cool.

Many plants that die to the ground during winter, called herbaceous perennials, bring garden color in September. The turtlehead plant (Chelone glabra) is a good example that grows in U.S. Department of Agriculture plant hardiness zones 3 through 8. It's about 2 feet tall and has pink-shaded white flowers that resemble the heads of turtles. They start opening in August and continue into October. The perennial sunflower (Helianthus occidentalis) is another herbaceous perennial that's also native to parts of the U.S. It grows year-round in USDA zones 4 through 8, starts blooming in August and continues through September. Its flowers are daisylike and bright orange-yellow.

Some plants delay their bloom until September and continue until winter arrives. For example, the white snakeroot plant (Eupatoroium rugosum) only begins blooming in September -- it puts out fluffy white flower clusters throughout fall, only stopping when weather chills. This plant can be 5 feet tall and grows in USDA zones 3 through 8. Chrysanthemums (Chrysanthemum spp.) make up a large group of garden plants that generally start bloom periods in September. They grow in USDA zones 5 through 9, are 1 to 3 feet tall and have flowers in many colors and shapes, depending on the variety. For example, the cultivar "Single Apricot" (Chrysanthemum "Single Apricot") starts blooming in September and continues through fall and has pale apricot flowers with yellow centers.

Some plants that have a shrubby growth habit also bloom in September. The panicle hydrangea (Hydrangea paniculata) is a member of this group that grows in USDA zones 3 through 8. It's a large, spreading plant about 8 feet tall and 6 feet wide with pyramidal clusters of white flowers that start in July or August and carry on through September. The bluebeard plant (Caryopteris x clandonensis "Lisaura" Hint of Gold) is another example -- it begins flowering in late July and continues through September, putting out clusters of dark blue flowers at the ends of branches covered in variegated, yellow and green leaves. It grows as a 3-foot-tall plant in USDA zones 5 through 9.

Some annuals also make good choices for a fall-blooming garden, brightening up flower beds late in the season. The common pansy (Viola x wittrockiana) is a good example of a plant that blooms in cool weather. Although often grown in spring, plant pansies in late summer to enjoy flowers that appear from September through fall and only stop when cold weather arrives. These plants can be perennial in USDA zones 6 through 10, but are usually grown as annuals. The nasturtium (Tropoaeloum spp.) is another annual that flowers in September. It starts blooming in spring, and then slows flowering during summer's heat, but puts out a second, lesser crop of flowers when the weather cools in September. Funnel-shaped nasturtium flowers can be red, orange, yellow or cream, depending on the variety.