Land Plants - invasive

Japanese Knotweed (Fallopia japonica) on Mar 24, 2026

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

Description of specimen

Small, redish, growing on rocks.
My Seek app identified it as Japanese Knotweed.

Commentary

Avatar of commenter Great photos! These kind of clear, close up photos provide an easy identification of the famous Knotweed. There has been some bio-control applied to Knotweed just down stream of this location; applied by Oregon Department of Agriculture. Knotweed has spread throughout Tillamook County and surrounding counties. There has been tremendous effort made by Tillamook Soil & Water Conservation District, landowners, and partners to control the population density for over a decade.
ODA has Knotweed listed as a state "B" listed noxious weed.
For more information on how to control noxious weeds, please visit our website:
https://tillamookcountyswcd.org/

Michael Blankenship, TCSWCD

Michael Blankenship
March 25, 2026, 7:47 a.m.

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

The Japanese Knotweed was on rocks at Nehalem Falls - down the walking path to the falls.
45.72653, -123.77196

Expert Reviewer

Avatar of Reviewer

Michael Blankenship
Tillamook Soil & Water Conservation District

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