How to eradicate Oregon Grape - Ask Extension
What is the best way to eradicate Oregon Grape?
Knowledgebase
How to eradicate Oregon Grape #929846
Asked April 27, 2026, 8:56 PM EDT
What is the best way to eradicate Oregon Grape?
Washington County Oregon
Expert Response
Thank you for your question, Lisa. "Oregon grape", horticulturally speaking, is a Mahonia, and there are several native varieties in the PNW. (https://landscapeplants.oregonstate.edu/plants/mahonia-nervosa and https://landscapeplants.oregonstate.edu/plants/mahonia-aquifolium)
It is our state flower, and OSU would not classify it as a "pest", so there is no advice for exterminating it. In fact, most of the academic literature advises on how to kill its pests. (https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/mahonia.html).However, removing its roots physically, or using an herbicide labelled to be effective on holly plants should work. Just know that you are killing a plant of value to wildlife.
It is our state flower, and OSU would not classify it as a "pest", so there is no advice for exterminating it. In fact, most of the academic literature advises on how to kill its pests. (https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/mahonia.html).However, removing its roots physically, or using an herbicide labelled to be effective on holly plants should work. Just know that you are killing a plant of value to wildlife.
