Swamp milkweed grows 4–5 feet tall and has clusters of pinkish-purple buds that open to invite butterflies mid to late summer. After blooms fade, 4–5-inch long seed pods develop then split open to release seeds that catch and ride the wind with puffs of silky threads. Upright and clump-forming, this beauty is slow to establish and slow to emerge in spring...but once settled in it sends out DEEP taproots. So make sure you plant it where you want it to stay for good. While it does spread via rhizomes, it is said to be considerably more compact and small-garden-friendly than A. speciosa, Showy Milkweed.
This native to the eastern U.S. tolerates clay soil, wet soil, and deer, naturalizes, and is fragrant! It's native to North American swamps and wet meadows but will tolerate less water.
Mature size: 4–5 feet tall & 2–3 feet wide, though can spread wider in lush conditions.Minimum temperature: -20° F