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Flathead County Weed Control District (The District) directly manages roadside noxious weeds on County roads with a crew of seasonal employees that use a combination of herbicide treatments and mowing.  We also have contracts with various agencies to do weed management on their behalf.  Management of noxious weeds on private property is the legal obligation of the landowner.

No.  The Weed District is responsible for County roadway right-of-way noxious weed management and has contracts to do work for the Montana Department of Transportation and some other agencies.  The Weed District does not do work on private property.  Noxious weed management on private roads are the responsibility of individual property owners or the Homeowners Association, in some cases.

There is no “one size fits all” herbicide because each herbicide is specially formulated for control of specific plants and labeled for use in specific places.  Some can be used near water, while some cannot.  Some damage trees, while some do not.  It is important to know the environmental conditions of the specific area of use and be sure of the identity of the noxious weed pests being targeted.  It is recommended that you contact our office for an on-site consultation if you are not confident of these aspects.  You can get recommendations at a local ranch supply store if you are sure of your target weed species.  If using herbicide on your own be sure to thoroughly read the label as THE LABEL IS THE LAW.

Roundup is a non-residual, non-selective herbicide that will kill whatever vegetation it makes contact with.  When using any herbicide it is vitally important to read and follow label directions, including safety precautions.  THE LABEL IS THE LAW.  For more information please see the EPA website information regarding Roundup at  https://www.epa.gov/ingredients-used-pesticide-products/glyphosate

Mowing/cutting spotted knapweed alone is not considered an acceptable management method.  This is because spotted knapweed will adapt to consistent mowing by flowering just below the height of the mower blade.  The goal of noxious weed management is to not knowingly allow weeds to propagate or go to seed.  As such, mowing is only considered acceptable when used in combination with another method of management.

There are many reasons why herbicide treatment can be unsuccessful.  Herbicide that is old or has been allowed to freeze can become ineffective, the mixture rate could be off, or the equipment being used may be incorrectly calibrated.  While these are possibilities, the 3 biggest culprits for unsuccessful herbicide treatment are:

  • TIMING – for most of the noxious weeds of concern in the Flathead Valley spring (late May to mid-June) is the target window for herbicide treatment.  You really want to get the herbicide on the plant before it flowers.  For a select few, summer is the optimal time to treat them.  For some there is a second opportunity to spray them after the first overnight frost in the fall.  Since the timing can be species specific, it is extremely important to create your plan based on being sure of your target weeds.
  • PRODUCT - there is no “one size fits all” herbicide because each herbicide is specially formulated for control of specific plants and labeled for use in specific places.  Certain products work on certain weeds but won't affect others.  Some can be used near water, while some cannot.  Some damage trees, while some do not.  Some can be used in hay pastures, and some cannot.  It is important to know the environmental conditions of the specific area of use and be sure of the identity of the noxious weed pests being targeted.  For assistance, please contact our office.
  • SEED BANK – noxious weeds are categorized as such because they are tenacious and difficult to get rid of.  Many of the weeds on the noxious weed lists have seeds that can remain viable in the soil for a very long time, some even up to 25 years!  So, it is important to understand that a single treatment will not be enough to control a noxious weed infestation.  It is helpful to think of noxious weed management as an annual spring chore.

Our notification system is timed.  It is likely that the Weed Management Plan was not received by our office by the time the follow-up notification was sent out and the two passed in the mail.

If you have been contacted by our office or the Office of the County Attorney because noxious weeds have been identified on your property, this form is required by Montana state law: TITLE 7 CHAPTER 22 Part 21 2116&2132
The required form is located on our website under Forms & Documents.

The County Weed District does not have a financial assistance program. We can provide information and technical assistance and direct you to cost-share programs with other agencies. However, there are no programs available that will cover 100% of the cost of noxious weed treatment. Contact our office for more information.

Page Last Updated: Mar 6, 2023