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

A polygon shaped stem, multiple sections and stem like a bamboo, but the stem is really soft. Heart shape leaves. Dead old growth from last year dried and 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

Along the entire stretch of road in front of houses 1201 and 1207, along SE yew street. Patch starts in front of a house previously submitted, and continues alongside the entire fence line. It doesn’t seem to have crossed the street yet and currently seems contained to the median. However, there is a water drainage gate nearby that goes to the river. The median is a few hundred feet long and about 20 feet wide

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

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