This plant will produce only a rosette during the first year, so control during that time is critical. In its second year of growth this plant will produce many seeds which stick to animals, people, and vehicles. Houndstongue contains tumorigenic pyrrolizidine alkaloids which are toxic and can kill livestock

This weed has allelochemicals or allelopathies that act as a natural herbicide to inhibit other plant species from growing within their vicinity. Spotted knapweed is a highly adaptable plant. It can be found nearly everywhere in Montana. It will even adapt to mowing and grow shorter and shorter to bloom at very low heights, which is why this plant can vary in height from two inches to four feet.