Common Weeds in Small Pastures in Montana and Controlling Them

Below, we have listed some of the more common weeds we find in small pastures in the Bozeman area and Montana in general.



  • Houndstounge

    This plant is a bi-annual, the first year it will not flour and usually grow up to 12" tall. These leafs look nearly oval, waxy on bottom and hairy on top. The second year this plant can grow in excess of 3 feet tall and produce purple buds before producing all those tiny burr like seeds that stick to your socks or dog. Weed control on this state of Montana listed Noxious weed is often times tough because of the waxy leafs that prevent the herbicide from uptake.




  • Field Pennycress or "Fan Weed"

    This plant is the bane of many peoples existence. This plant mainly propagates by the spread of its seeds. One cool fact about this weed is that there is research being done that it could be a possible source for bio-diesel. Often times when trying to control this weed people call us too late in the season. To be effective when controlling this you need to get it when it is very young and ideally before it even has flours on it.




  • Canada Thistle

    Canada Thistle is one of the most common Noxious Weeds found in horse pastures and nearly everywhere else around Bozeman and Montana. This plant is very very easy to identify because of its jagged leafs and big purple plumes of seeds. Canada thistle is a perennial plant so it comes back every year. It spreads mainly by its roots which are a creeping rhizome, which means that when you see a big patch of this stuff that it all is interconnected. Weed Control with this plant can be very effective to nearly pointless. You truly need a herbicide that will work its way down into the root system of the plant and take out the "mother base." Control for this plant like most perennials is in the fall when the plant is taking all the nutrients it can down to its roots to store up for winter and the next year.





  • Common Tansy

    Common Tansy is very easily identified. This plant is a perennial rhizome plant like the canada thistle so control of this noxious weed would be a similar process. The most notable things about this plant are the fern like leafs and once it flours the bright yellow seed pods it sports. If you find that you have this on your property please take action to have it taken care of because this noxious weed left alone will propagate prolifically.




  • Knapweed

    Knapweed is one of the worst Noxious Weeds we have in Montana. There are a few species of Knapweed in Montana, spotted, russian and diffuse. Most common is the Spotted knapweed. This is a biennial or short lived perennial that can grow up to 3 feet tall and be green/ gray in color. The flowers are commonly pink to purple. Once established Spotted Knapweed takes over completely, control is extremely difficult but can be done successfully. This Plant spreads primarily by its seeds, One plant can produce thousands upon thousands of seeds that are then moved by wind, animals and people.