Light. Best in full sun. If it gets some shade, pinch the tips in early summer so it branches.
Water. Grows in wet to fairly dry sites and suits swales and the edges of wet areas. Water lightly in dry weather; established plants survive without it.
Soil and feeding. Handles sand, loam and even some clay. It responds to an occasional feeding but does not need it.
Size. Forms leaning, spreading clumps about 5 ft tall and up to 6 ft wide. Space plants 18–24 in apart.
Pruning. Trim now and then to keep clumps tidy. It spreads by underground stems; dig and divide new shoots to move or share them.
Problems to watch. Powdery mildew and spittlebugs show up but rarely do much damage.
Good to know. A Florida native that covers itself in yellow flowers in fall. Bees and butterflies visit the flowers, and birds and small mammals eat the seeds.
Sources: UF/IFAS Gardening Solutions: Swamp Sunflower · Florida Native Plant Society Plant Database: Helianthus angustifolius
