Here beach sunflower grows in front of a St. Petersburg Beach resort where it makes an attractive groundcover that protects the fragile dunes from erosion and tourists' foot traffic.
Beach sunflower may be erect, 3-4 ft (0.9-1.2 m) tall, or a much-branched, prostrate, spreading plant less than 18 in (46 cm) tall, but covering a couple square feet or more. The leaves are sand-papery coarse, heart-shaped, 2-4 in (5-10 cm) long and almost twice as wide at their widest. The flowerhead is about 2.5-3 in (6.4-7.6 cm) across, slightly nodding, and quite attractive. The rays are bright yellow, numbering 11-21, and about 1 in (2.5 cm) long. The disk is usually red-purple and about 1 in (2.5 cm) in diameter.
Most authorities recognize two subspecies of beach sunflower occurring naturally on beaches and dunes from southeast Texas to the east coast of Florida. Helianthus debilis subsp. debilis is prostrate and occurs along both coasts of the Florida peninsula. It has been introduced northward along the Atlantic Coast to North Carolina. H. debilis subsp. cucumerifolius (Cucumber-leaf sunflower) is erect and occurs along the northern Gulf Coast of Florida, west to Texas, and inland, especially in disturbed sites. The cultivar, H. debilis subsp. cucumerifolius 'Italian White', is up to 5 ft (1.5 m) tall with flowerheads 4 in (10 cm) across and pale yellow or creamy white rays and a black disk.
Culture Light:Full sun Moisture: Drought tolerant Hardiness: USDA Zones 8 - 11 . Propagation: By seed.
These are flowers of the prostrate form of beach sunflower.
The prostrate form of beach sunflower is often used as a ground cover or in mass plantings. It is used for dune stabilization, and is especially useful on banks and slopes in beach-front situations. Beach sunflower is well suited for borders along beach walkways. But you don't have to live on the beach to enjoy this rugged beauty. Plant it in full sun where you won't be able to water it and watch the butterflies visit to pay their respects.
Beach sunflower does well on calcareous soils and acid soils alike. It has a high tolerance for salt spray and salty soils and is very drought tolerant. This is in the same genus as the huge, upright annual sunflower, H. annuus.