Ageratina altissima

White Snakeroot (Ageratina altissima) is a perennial wildflower native to woodlands and shaded areas of eastern North America. It typically grows 2 to 4 feet tall, featuring clusters of small, fluffy white flowers that bloom from late summer into fall. This plant thrives in partial to full shade and prefers moist, well-drained soils, though it can tolerate some drought once established. White Snakeroot is an important nectar source for pollinators but should be handled with care, as all parts of the plant are toxic if ingested. It spreads by both seeds and rhizomes, forming attractive colonies in naturalized or woodland gardens.

Native range

Central & Eastern North AmericaNative here

Bloom time

August – October

Garden location

Northwest Shade Bed