Knotweed is a species of increasing concern with several new populations across Anoka County. Knotweeds are herbaceous shrubs characterized by a sturdy, bamboo-like stalk which can grow to over 10 feet in a single season. They grow aggressively, especially along riparian areas where they outcompete native vegetation and create bare ground which enhances erosion damage. Knotweed can also grow through sidewalks and concrete foundations, damaging infrastructure.
There are three species of knotweed in MN: Giant, Japanese, and Bohemian which is a hybrid of the first two. All three Knotweed species are on the state noxious weed list as Prohibited Control species. Efforts must be made to stop their spread and propagation. Late August into September is the easiest time to spot Knotweed infestations due to their showy white flowers. You can help keep this species under control by entering sightings into EDDMaps or reporting them to ACD staff.
For more information contact Logan Olson, Restoration Technician, at