Keeping invasive plants out of our prairies is a never-ending battle. If left unchecked, they can take over an area and exclude native plant species. Tremendous effort goes into controlling invasive plants. We try to use the least intrusive control methods possible, including hand pulling, mowing, grazing or haying, or if necessary, chemical treatment with either spot spraying or broadcasting in larger areas. Chemical treatment must be done carefully, because it can harm native plants, too.