Swamp Sunflower

Helianthus angustifolius

Swamp sunflower is autumn's most generous plant. In October, six to seven feet of narrow-leaved stems erupt into hundreds of small bright yellow flowers with dark chocolate-purple centers. a color combination so satisfying that it looks designed. The fine-textured foliage stays clean and fresh all season before giving way to this final extravagance at the tail end of the growing season, just as everything else is fading. Despite the name, it grows well across a broad moisture range, from moist to average garden soil, with only brief wet periods tolerated. It spreads by rhizome to form a colony over time, which means it's best in spaces with room to expand or naturalized areas along a stream or pond. This plant earns its spot with sheer fall volume.