Submitter does not have a specimen
Well established plant some 10 feet up steep hillside. Multiple stems at least 1 inch diameter.
Oregon State University's Solve Pest Problems page has some great information about how to get rid of knotweeds Solve Pest Problems
This is a tricky weed to manage. Consider reaching out to your local Soil & Water Conservation District for technical advice.
Back slope of housing development, butted up against Sunnyside Rd. Fairly steep hill, between back fence of property and sidewalk.
Jacob Rose Institute for Natural Resources
© 2025 Portland State University | Contact us for questions regarding site content