Perennial sunflowers (Helianthus spp.) drop their seeds in fall and return again as the sun warms the ground in springtime. Some varieties spread by increasing their clump size. Sunflowers provide a tall background plant for a perennial bed in the garden or a perennial portion of a garden with annual flowers used as accents. They come in colors ranging from bright yellow to deep maroon, often with velvety-brown centers.
Silverleaf sunflower (Helianthus argophyllus) is a perennial sunflower variety with a purplish-brown flower center surrounded by bright golden petals. Its stems and leaves are covered with silky gray down on the younger plants, which are often used in dried flower arrangements. It grows 5 to 6 feet tall in U.S. Department of Agriculture plant hardiness zones 8 through 10 and would be a good perennial background plant for annuals such as zinnias (Zinnia elegans), bachelor buttons (Centaurea cyanus) or marigolds (Tagetes spp.). Cucumberleaf sunflower (Helianthus debilis) has multiple branches, a profusion of yellow flowers and grows 3 to 4 feet tall. This variety is a smart addition to a perennial garden bed dedicated to cut flowers. It grows in USDA zones 8 through 11.
“Lemon Queen” sunflower (Helianthus x laetiflorus “Lemon Queen”) is a shrub-type perennial that reaches 1 to 6 feet tall. It grows in USDA zones 4 through 9. “Flore Pleno” sunflower (Helianthus multiflorus "Flore Pleno"), which grows in USDA zones 4 through 10, produces 2 1/2-inch double gold colored flowers that bloom in late summer. Sunflowers do best in a full-sun spot in the garden with soil that drains easily. Perennial sunflowers have long taproots that retain water and help stabilize the taller varieties. Young sunflowers track the sun from east to west throughout the day, but this action declines as the plant matures.
Sunflowers in a perennial garden attract hummingbirds, butterflies, beneficial insects and birds, which help reduce harmful insect pest populations. Finches and sparrows have the strong beaks to break open sunflower seeds, and these birds also feed on unwanted insects. Sunflowers are pollinator-friendly plants that attract bees to the garden, which pollinate garden plants, vegetables and fruits. Butterflies are also garden pollinators that are attracted to the sunflower’s bright colors. Grow perennial sunflowers near the vegetable garden to help contain unwanted caterpillars, slugs and snails.
Care for a Perennial Garden
Perennial sunflowers return and spread in the garden and need to be divided or thinned every two to three years. Reduced flower size and loss of plant vigor are signs the plant needs more growing space. Divide or thin in spring as new growth begins for the year. Re-seeding perennial sunflowers send up new plants each year that can be transplanted to other areas of the garden. Keep weeds under control in a perennial garden by lightly cultivating the top inches of soil.
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