Right before our eyes, landscapes are being transformed back into native grassland species. Spotted knapweed reduces forage for wildlife and can double the amount of soil erosion when it invades rangeland. It was introduced by settlers from Europe in the early 1900s. Knapweeds are highly competitive and will readily establish on any soil surface. They release a chemical substance which inhibits surrounding vegetation from growing and are not grazed by wildlife because of their bitter taste and high fiber content.
People are the main reason knapweed is spreading across the country.
Seeds are being transported by vehicles, contaminated hay, livestock, and wildlife. The park has spotted knapweed along road corridors and at the Painted Canyon Visior Center area. Luckily the plant is easy to control if we can find it early. The most effective treatment for knapweed is to apply herbicide. Biological controls are available but their success has been limited.