New York Ironweed

The deepest purple of any native late-summer perennial, and a monarch magnet during peak migration. nothing else delivers that combination.

New York Ironweed announces itself in late summer with clusters of the most saturated purple flowers in the native plant palette, a color so intense it looks almost artificial against the blue late-summer sky. Growing four to seven feet in moist soils, it's a back-of-border presence that earns its footprint during the six-week window when monarchs are migrating and nectaring pollinators are at peak activity. The flat-topped flower clusters open in August and hold through September, followed by russet seed heads that goldfinches work through the fall. This is a meadow and rain garden plant at heart, native to moist, low areas along stream banks and wet meadow margins throughout the mid-Atlantic. It spreads modestly by rhizome and self-seeds, which makes it ideal for naturalizing in difficult low spots where drainage is slow. Cut it back hard in late June to reduce height by a foot or two and encourage branching, or let it run tall and stake if needed. Either way, the pollinator payoff in late summer is enormous.