Japanese Knotweed - Ask Extension
I have Japanese Knotweed in my backyard, it’s been here for years, but I’ve only now researched it and learned that it is pretty destructive. Any ...
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Japanese Knotweed #934503
Asked June 07, 2026, 10:22 AM EDT
I have Japanese Knotweed in my backyard, it’s been here for years, but I’ve only now researched it and learned that it is pretty destructive. Any advice on getting rid of it would be appreciated.
Ramsey County Minnesota
Expert Response
Thank you for writing.
This paper is pretty complete. I suggest the stem application method. Do not try to dig them out. Do not compost. Send to a lawn waste center.
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.nwcb.wa.gov/images/weeds/Knotweed-Control_Whatcom.pdf
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.cal-ipc.org/wp-content/uploads/2017/12/17845.pdf
Unfortunately, these tools are quite expensive, a professional may be better. If you elect to spray glyphosate, be sure to follow instructions, do it on windless days, and move backwards so you do not pick up the chemical on your shoes and track it to other areas.
This paper is pretty complete. I suggest the stem application method. Do not try to dig them out. Do not compost. Send to a lawn waste center.
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.nwcb.wa.gov/images/weeds/Knotweed-Control_Whatcom.pdf
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.cal-ipc.org/wp-content/uploads/2017/12/17845.pdf
Unfortunately, these tools are quite expensive, a professional may be better. If you elect to spray glyphosate, be sure to follow instructions, do it on windless days, and move backwards so you do not pick up the chemical on your shoes and track it to other areas.
