- Contact information
-
For information on Lakes in Wisconsin, contact:
- DNR Lake
Division of Water
Bureau of Water Quality
- Aquatic Invasive Species Contacts
Giant knotweed (Polygonum sachalinense) - W. Bigelow St.
- Status
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Verified and Vouchered
- Date First Found
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9/29/2021
About
Giant Knotweed
Giant knotweed is a herbaceous perennial that can reach 9’ tall with erect, hollow stems that resemble bamboo. The stems are smooth and arching with swollen nodes and twigs that zigzag from node to node. Giant knotweed invades riparian areas where it prevents streamside tree regeneration. It is often found in floodplain forests, disturbed areas, roadsides, and vacant lots. Plants form dense stands that crowd and shade out native vegetation.