I’m having difficulty removing knotweed from my garden. Can you give me advice on how to eradicate it?
I’m sorry to hear you are struggling with knotweed. Manual methods include
cutting, mowing, pulling, digging, or covering. Dig surface roots in
loose soil. Check frequently for new shoots and dig them up as soon as
you notice them. Cut stems close to the ground every two weeks throughout
the growing season. After cutting completely, you could instead decide
to cover the area of the knotweed patch and the immediate area around it
with black plastic or other impermeable material. This is a long-term
process, and it may take several years to eradicate the Polygonum. Here are some helpful links on knotweed:
Invasive Knotweeds from the King County Noxious Weed Control Program
Knotweed Biology and Control from the King County Noxious Weed Control Program
Controlling Knotweed in the Pacific Northwest (a large file!)
Japanese Knotweed from the PCA Alien Plant Working Group