Helianthus debilis – Often called beach or dune sunflower, this Compositae family member is a herbaceous perennial, Florida native wildflower that can be use as sprawling groundcover or border plant in many full sun, low maintenance environments.
Size/Habit/Lifetime: Best if planted on 2 to 3 foot centers, beach sunflower can cover a 3×5 area if given space. Height generally below 24 inches unless allowed to clump heavily. Beach sunflower forms a dense mat of clumping stems that form from underground runners. It is a perennial in central to south Florida, but reseeds readily in more northern environments.
Culture: Zones 8-11. Beach sunflower prefers well-drained, hot and sunny locations and can tolerate light shade. Very salt resistant, prefers light irrigation. tolerates most soil types, prefers sand. Most at home on beach dunes where it thrives on very little water.
Leaf/Stem/Trunk: Leaves are simple, alternate, deltoid shaped with dentate margins, and sized from 2-4 inches. Color is light to pale greenStems are semi woody before dying back over a hard frost.
Flower/Fruit: Pale yellow ray flowers with a dark center disc measuring 1/2 – 1 inch in diameter. Blooms almost year round, mostly spring and summer.
Use: Beach sunflower is a popular groundcover in beach environments but can be used in many areas. Best in large massing with other spreading wildflowers, particularly Gallardia sp., and Coreopsis sp.(above). Can be mainatained as a border plant or in a converted annual bed. It is beginning to be used in medians and commercial landscapes for its year round flowering and butterfly attractant. Time and maintenance efforts will tell if this is a viable option. Also, is can be suitable to greenroof applications!
Notable Fact: According to Plants of the Medical Garden from Palm Beach State College. This native plant has been used for color dyes, as a diuretic and expectorant, oil from seeds used for snake bites and sunstroke, leaves eaten as a vegetable, and burnt stems as potash fertilizer.