Japanese Knotweed flower and leaves

Japanese Knotweed leaves

Japanese Knotweed

Japanese knotweed (Polygonum cuspidatum Sieb. & Zucc.), a member of the buckwheat family, was introduced into the U.S. from Eastern Asia in the late-1800s. By the late-1930s, it was viewed as a problematic pest. The plant, which can grow from three to 15 feet tall, has bamboo-like stems and is sometimes called Japanese bamboo. As with many invasive plants, knotweed thrives in disturbed areas and once established can spread rapidly, creating monoculture stands that threaten native plant communities (from The NY Invasive Species Clearing House).


The New York Invasive Species Clearing House (CCE Invasive Species Program) provides information on biology and identification, impacts, prevention and control, additional resources and links to educational materials.

USDA Plant Profiles provides background, maps of U.S. distribution, and links to selected federal, state and regional resources. 

US Forest Service Fact Sheet(1-page PDF) includes photos, national distribution, impacts and information on control and management.

Minnesota Dept. of Natural Resources includes suggested alternatives, control methods, and additional resources.

Last updated December 13, 2023