Weeds in lawn - Ask Extension
Need help identifying weed taking over our lawn and how to treat it.
Knowledgebase
Weeds in lawn #924467
Asked February 11, 2026, 3:42 PM EST
Need help identifying weed taking over our lawn and how to treat it.
Washington County Oregon
Expert Response
Need help identifying weed taking over our lawn and how to treat it.
Gina, I’m sure it’s taking over! It’s most certainly Quackgrass and it spreads by rhizomes which run at the surface or slightly underground for a long distance. As you have no doubt learned.
There are two was to get rid of it. You can dig it out but it will re-grow from even a small piece of root.
Or you can poison it with a selective herbicide, particularly one which mentions Quackgrass on the back and contains 2,4-d and dicamba. If you use poison please follow all safety guidelines.
Good luck!
Susan, Yamhill County Master Gardener
