Combating New Weeds in Central Oregon

Asked March 19, 2020, 2:41 PM EDT

Hello Master Gardener, I live in Powell Butte and last year we had a new weed crop up EVERYWHERE that was a pain. I assume the snow pack contributed to it. The plant produces round sticker balls. Do you know what they are and what I can do to prevent them spreading this year? We don't have sod grass but a variety of natural grasses in our yard, and weeds(well, one small area of nice sod grass). I would love to treat the whole yard with something to encourage the grasses and discourage the weeds. There's a broad leaf plant taking over everywhere this year. Pictures provided. Thank you! Susan

Crook County Oregon

3 Responses

It sounds like it could have been Horehound? It would appear that the weeds you have greening up now are some species of mustard - could be tansy mustard, flixweed, Jim Hill mustard, etc. They are winter annuals. Broadleaf herbicides that are rated "good" on mustards include 2,4-D, MCPA, or a mixture of these two. (Nothing was rated excellent) Also use a wetting agent (sticker/spreader) to mix with it to make the herbicide work better. Read the label on the product and follow directions. you can also clip the weeds and these dryland grass down to about 6 inches to keep the weeds from growing to seed.

Mylen Bohle
Area Extension Agronomist
OSU Crook County Extension Service
498 SE Lyn Blvd,
Prineville, OR 97754
Ph: 541-447-6228
Email: Mylen.bohle@oregonstate.edu

Hello Mylen,

Thanks on the help with the leafy weeds-mustard variety. I think I figured out the one with the stickers, I believe it’s lawn burweed. See attached pictures. I have not figured what would work to kill them, perhaps what you suggested would help.


Susan

Looks like it could be Bur buttercup. Yes try the same herbicides on it.