10/17/2026
Helianthus angustifolius, Swamp Sunflower, is a tall, late-blooming perennial of wet meadows, low ground, and sunny garden edges.
By late October, when much of the garden has begun to recede, its stems rise six to eight feet and open into clear yellow flowers.
It belongs to the Aster family, and looks especially at home among its relatives: the purple flowers of New England Aster, the white of Flat-Topped Aster. Around it may stand Mountain Mint, Blazing Star, Boneset, and grasses—species whose roots, stems, and habits help make a planting feel less like a collection and more like a community.
Swamp Sunflower prefers average to wet soils and partial sun, though it is adaptable. In full sun, and even through periods of drought, established plants can prove surprisingly resilient.
Its foliage is host material for several native butterfly caterpillars. Its late-season flowers provide pollen and nectar at a time when floral resources are becoming scarce. Later, the seeds feed songbirds through winter. In spring, deer may browse the emerging leaves and stems.
So the plant participates in the garden in several directions at once: flower, forage, shelter, structure.
It is especially well suited to pollinator gardens, rain gardens, and naturalistic plantings where moisture and height can be used rather than controlled.
We grow Swamp Sunflower in our own rain garden and have plants available at the nursery now.
At the moment, it is in bloom: tall, yellow, and difficult to overlook.
