Helianthus angustifolius

Common Names

Swamp Sunflower, Narrowleaf Sunflower, Sunflower

Summary

Swamp sunflower, Helianthus angustifolius, is a native eastern U.S. perennial that forms an upright clump with fibrous roots, typically 5–8 ft tall, with erect, often hairy stems and narrow, linear to lanceolate leaves (8–15 cm long) having revolute margins and a strigose to hirsute abaxial surface, it bears 3–16 heads on peduncles 5–15 cm long, ray florets 10–20, and many disc florets with yellow ray florets surrounding yellow discs, flowering from late summer to fall in moist open to shaded habitats and range from New York to Florida west to Texas, inland to southern Ontario, with a FACW wetland indicator status, for cultivation, plant in full sun with moist to wet soils, tolerating acidic to neutral pH and coastal salt air, it propagates by seed or division, with clumps typically divided every 2–4 years and may reseed, sometimes requiring staking in exposed locations, pruning in early summer encourages branching, maintenance is generally low, with deer resistance and few pests though rust and powdery mildews can occur, it is well suited to native pollinator and wildlife gardens, rain gardens, and naturalized borders, attracting bees, butterflies, and birds

Lifecycle

Perennial, Annual, Biennial

Height

5-8 feet

Spread

2-4 feet

Hardiness Zones

Zones 5-9

Sunlight Requirements

Ideally Full Sun, tolerates Partial Shade, Full Sun to Partial Shade

Soil Type

Moist, well-draining loamy soil rich in organic matter

Soil Drainage

Moist but well-drained soil.

Soil pH

5.0-7.5

Bloom Color

Yellow

Bloom Time

Fall

Foliage Color

Green

Fall Foliage Color

Green

Leaf Lifecycle

Deciduous

Growth Rate

Moderate, fast-growing in moist, well-drained soil

Seasons of Interest

Summer and Fall

Propagation Methods

Seeds, Division

Attracts Wildlife

Bees: Yes, Butterflies: Yes, Other pollinators: Yes, Birds: Yes, Hummingbirds: Unknown