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Mitigating desert madwort #869074
Asked May 18, 2024, 11:33 PM EDT
We recent built a house west of denver at 7,700 feet. Much of the land we disturbed during the build is being taken over by desert malwort. How do we mitigate it? We are talking 3+ acres. Is there a spray, should we mow it. It’s all starting to bloom now. It has coked out our native mountain field grass.
Jefferson County Colorado
Expert Response
Thank you for your question. Annual weeds, like Desert Madderwort and other members of the weedy Brassica family require a multipronged approach, probably over several seasons.
Mechanical
- If the plants haven't already gone to seed, then they can be mowed to prevent seed formation.
- If they have gone to seed, then, mow with a collecting bag and discarding seed.
- Apply pre-emergent herbicides that target the annual weeds, as opposed to perennial grasses. The common example is the pre-emergent herbicide Preen, containing the active ingredient trifluralin.
References:
- Wild Mustard https://wric.ucdavis.edu/information/natural%20areas/wr_S/Sinapis.pdf
- Weed Management for Small Rural Acreages https://extension.colostate.edu/docs/pubs/natres/03106.pdf
- Desert Madderwort https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_alde.pdf
- Controlling Mustard Weeds (Kansas State) https://www.ksre.k-state.edu/news/stories/2023/11/agronomy-mustard-weeds.html
Mari H
One follow on. “gone to seed” all our are now blooming, do we need to rake them up of we mow?
From: "ask=<personal data hidden>" <ask=<personal data hidden>> on behalf of Ask Extension <<personal data hidden>>
Date: Thursday, May 23, 2024 at 9:57 PM
To: Kevin Custer <<personal data hidden>>
Subject: Re: Mitigating desert madwort (#0138995)
THANK YOU, you folks always know best.
From: "ask=<personal data hidden>" <ask=<personal data hidden>> on behalf of Ask Extension <<personal data hidden>>
Date: Thursday, May 23, 2024 at 9:57 PM
To: Kevin Custer <<personal data hidden>>
Subject: Re: Mitigating desert madwort (#0138995)
Yes, for best control rake/collect the mowings and discard. Do not compost.
Let us know of any other follow up questions.
Best,
Mari
