Japanese Knotweed

Asked August 28, 2020, 4:26 PM EDT

I believe I have found Japanese Knotweed growing all over in our area and some also on our property. It is thick in the woods along Lost Creek in Dexter. Can someone please tell me how to get rid of it on our property as it is highly invasive?

Lane County Oregon

1 Response

Thank you for reaching out to OSU Extension Service. You are correct, knotweed species are highly invasive. Chemical control is often required to manage knotweed. The following publication provides details about which herbicides are effective and common management mistakes, such as mowing and handpulling which create thicker stands. Biology and Management of Knotweeds in Oregon: https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9031.pdf

Additional herbicide information is available in our PNW Weed Management Handbook: https://pnwhandbooks.org/weed/problem-weeds/knotweed-bohemian-polygonum-bohemicum-japanese-polygonum...