Pictured above: Dune sunflower (Helianthus debilis) by Stacey Matrazzo. Click on terms for botanical definitions. View post as a PDF.
Dune (or beach) sunflower(Helianthus debilis) occurs naturally along the coast but adapts well for inland use. It typically blooms in summer, but may flower year-round in South Florida. Its bright flowers attract a variety of pollinators, including butterflies, moths and bees. Its dense growth pattern provides cover for many small animals, while its seeds are eaten by birds.
Yellow daisy-like flowers consist of brownish-red disk florets surrounded by bright yellow ray florets. Leaves are deltoid-shaped, with rough surfaces and toothed margins; they are alternately arranged.
Family: Asteraceae (Aster, daisy or composite famiily)
Native range: H. debilis is native only to the counties along the east coast. However, there are two subspecies: cucumberleaf dune sunflower (H. debilis subsp. cucumerifolius), which is native to scattered counties throughout the Panhandle and a few peninsular counties; and west coast dune sunflower (H. debilis subsp. vestitus), which is endemic only to Pinellas, Hillsborough, Manatee, Sarasota, Charlotte and Lee counties. (See caution below.)
To see where natural populations of Dune sunflower have been vouchered, visit florida.plantatlas.usf.edu (east coast dune sunflower), florida.plantatlas.usf.edu (cucumber leaf dune sunflower) and florida.plantatlas.usf.edu (west coast dune sunflower).
Soil: Dry, well-drained sandy soils
Exposure: Full sun
Growth habit: 1-2’ tall with 3-4’ spread
Propagation: Seed, cuttings
Garden tips: Dune sunflower can tolerate salt and wind. Plant in full sun for best flowering. It is a prolific self-seeder, and has a tendency to spread quickly if not maintained. Periodic removal of spent plants is recommended. Depending on the variety, this plant may be spreading or upright. As a groundcover, it may sprawl several feet but generally is no more than 2 feet high. West coast dune sunflower can be taller.
Caution: All subspecies are capable of hybridizing and should not be planted together. When using in a landscape or garden setting, it is recommended that the subspecies native to/appropriate for the region be used. Environmentally conscientious gardeners living along the coast should ask their nursery for the subspecies native to their locale. This will help preserve the distinct identities and ecological roles of these plants.
East coast dune sunflower seeds are available through the Florida Wildflowers Growers Cooperative. Plants are often available at nurseries that specialize in native plants. Visit PlantRealFlorida.org to find a native nursery in your area.
For more information on other Helianthus species, see these resources: