Montana knapweed researcher sees work paying off

Montana knapweed researcher sees work paying off. By Perry Backus. Missoulian.

Aside from cheatgrass, the spread of the knapweeds: spotted knapweed, diffuse knapweed, Russian knapweed, and yellow starthistle, is probably the biggest exotic noxious plant problem in the West.

Like cheatgrass, its adverse effects are often unappreciated by the casual observer of wildlife or those into single cause explanations of wildlife population sizes.

So this is good news except that noxious annual cheatgrass often replaces the dying knapweed because the seeds of native perennial plants have decayed away.
Image of spotted knapweed.

Image of yellow starthistle






  1. TPageCO Avatar

    Ralph- You’re right on with your comment about cheat replacing knapweed. That’s exactly what I’ve seen on our ground. One of the biggest problems with restoring these areas is having enough native seed sources around to prevent cheat or crested wheat from filling the gap after the knapweed is removed.

  2. Ralph Maughan Avatar

    A business that grows native plant seeds would be a great opportunity. The demand grows each year.

    It would also be a new kind of agricultural business opportunity for rural areas.

  3. buffaloed Avatar

    I am seeing spotted knapweed more often in Valley County and I worry that it will return with a vengeance to my place where I have diligently pulled it over the years. I hope that we can avoid a massive infestation of it here with these kinds of biological controls. I am very worried about the back country now that everything has burned. I don’t want it to end up like the Selway has. Fortunately we don’t have large infestations of cheat grass this high and many areas still have mostly native plants but that could change with the climate and the fact that the fires have disturbed the soils giving knapweed a good clean slate to start from. At least this is on the radar of some people and work is being done. In places that I have seen knapweed in the past and reported it there has been some action to remove it and it has been successful.

  4. Layton Avatar

    Biologicals aren’t having a lot of luck — in the Payette N.F. anyway — seems that the winters up there are pretty rough on the bugs. Down in Hell’s Canyon they are doing a lot better — not as much cold in the winter.

    The best approach that we have come up with lately for really controlling Knapweed is waiting until it flowers in the fall, then “beheading” it manually and spraying the remaining plants with Tordon. Next year — no knapweed!! Of course it’s pretty rough to do with a large infestation but it works really well on small ones. The flowers need to be burned because the seeds inside are probably already viable.



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Ralph Maughan