Noxious weeds are invasive plants that the State of Montana has declared a nuisance. These plants are harmful to the native environment, croplands, and livestock. Noxious weeds were intentionally, or accidentally, introduced from Europe and Asia. They do not have naturally occurring enemies here (predation, disease) and this allows them to flourish.
Over the past century, noxious weeds have infested about 9% of Montana’s land area, causing economic and ecological harm. It is estimated that leafy spurge and spotted knapweed have caused production in Montana ranches to fall by 0.7 to 0.8%. Weeds disrupt native ecosystems and take over native plants. This has widespread impacts that affect wildlife, water quality, and scenic values.
Living on the Bank created this informational video regarding Noxious Weeds in Montana.
Noxious weeds of Montana, pictures, identification tools, and treatment techniques are listed at https://www.mtweed.org/weeds/weed-id/. Some of the most notable noxious weeds in Montana are:
In Montana, you are required, by law, to manage noxious weeds on your property.
- “It is unlawful for any person to permit any noxious weed to propagate or go to seed on the person’s land, except that any person who adheres to the noxious weed management program of the person’s weed management district or who has entered into and is in compliance with a noxious weed management agreement is considered to be in compliance with this section.” (Title 7, Chapter 22, Part 21)
- It is important to develop a weed management plan with your county weed district and to gain approval by your local weed board.
- Application of certain pesticides requires an applicator training course through MSU Extension.
- Seedbanks are live seeds that are present on land even when the mature plant is not. Seedbanks can remain viable for years. Learn more about the seedbank characteristics and management through this University of Nevada resource.
The Montana Weed Control Association has a wealth of resources on weed identification, treatment, and planning.
For more information on the Noxious Weeds in Montana – Montana Noxious Weed Awareness – Responsive Agency Template
The Montana Department of Agriculture has programs available for Noxious Weeds.