Land Plants - invasive

Japanese Knotweed (Fallopia japonica) on Apr 23, 2026

Submitter does not have a specimen
EDRR Status: Local expert notified

Description of specimen

Pentagonal, hallow stem, with sections, like a bamboo, but very soft. Heart shaped leaves. Old dry stalks from last season visible.

Commentary

None

Remedy

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.

Location

Japanese knotweed in a yard mixed in with a lot of blackberry and an evergreen bush.

Expert Reviewer

Avatar of Reviewer

Samuel Leininger
Clackamas Soil and Water Conservation District
4-County Cooperative Weed Management Area
Columbia Gorge Cooperative Weed Management Area

Maintained by Oregon State University | Contact us for questions regarding site content