Noxious Weeds

Asked November 13, 2017, 7:20 PM EST

I am trying to clear my property of Knapweed and Puncture vine, and I would like to ask if there are certain chemicals that would work better than others? Also I have a small lot so if there were smaller option that wasn't for a huge farm.

Jefferson County Oregon

1 Response

Hi, thanks for sending in your problem. You indicate that you have a small lot, both of these weeds respond well to pulling, hoeing or digging out before they flower and reseed. On a small lot that is usually the best recommendation though it takes dedication and constant monitoring. Since it sounds like you have an established weed issue I would recommend an integrated approach of using chemicals along with mechanical methods (pulling) for a year or two. After a couple of years the number of weeds should decline enough that hand pulling will suffice. I am attaching a few links that I think explain the use of chemicals very well for these two weeds. A bonus is that the chemical treatment will also control many other weeds too. You didn't indicate if the weeds were in bare soil areas or in grassy areas but the articles include management for both circumstances. Be sure to follow the advice for your situation. Since you do have a small lot and you are concerned about buying large quantities of chemical I recommend that you purchase ready-to-use products. These are premixed in appropriate dosage so you don't have to do any measuring or mixing and are not left with large amounts of concentrated chemicals.

https://cals.arizona.edu/yavapai/anr/hort/byg/archive/controllingpuncturevine.html http://ipm.ucanr.edu/PMG/PESTNOTES/pn74128.html https://www.nwcb.wa.gov/pdfs/Knapweed-Control_Whatcom.pdf