Managing noxious weeds in Montana

Montana law states that “it is unlawful for any person to permit any noxious weed to propagate or go to seed on the person’s land.” It further states that “…any person who adheres to the noxious weed management program of the person’s weed management district or has entered into and is in compliance with a noxious weed management agreement” is considered to be in compliance. (Montana Code 7-22-2116 (2023)).

Legally, a noxious weed is any plant designated by a Federal, State or county government as injurious to public health, agriculture, recreation, wildlife or property. Montana Noxious Weed List includes 36 plant species ranging in priority from 1A and 1B to 2B, and five regulated plant species.

The first step in any well executed project is to identify the goals and create a plan that is both realistic and effective. Managing noxious weeds begins with plant species identification, includes taking an inventory of the level of infestation, and involves creating an action plan that is viable.

Invasive plants thrive on disturbed soil and seeds are distributed by many vectors including birds, wind, wildlife, livestock, humans and all sorts of vehicles. Some invasives also have aggressive root systems that spread long distances, often from a single plant. Noxious weeds and other non-native invasives left untreated become established, quickly reproduce and spread and cause harm to the environment as well as the economy. Invasive species compete directly with native and desirable species for moisture, sunlight, nutrients and space. Populations unchecked cause major change faster than native ecosystems can accommodate.

The most effective approach to controlling noxious weeds is the implementation of integrated weed management (IWM), the integration of effective, dependable and workable weed management practices such as cultural (e.g. pulling weeds), mechanical (e.g. mowing), chemical and biological that can be used economically.

Powell County Weed District and Missoula County Department of Ecology and Extension work with land owners and managers to promote IWM practices including site visits and vegetation management plan development, loaner equipment programs, cost-share grants, revegetation tools, biological control with insects, organized weed pull events, outreach and education events and no-cost materials such as weed ID books. We offer plant identification and also provide contact information for licensed spray contractors and other resources that promote healthy land use practices.

I would encourage anyone seeking advice on noxious weed management to contact their local county weed board coordinator or Ag Extension Agent. County coordinators and Ag Extension agents are trained and licensed and provide the most accurate and up to date options and resources for managing noxious weeds.