The War on Weeds

Rocky Mountain National Park maintains a constant watch on its botanical resources, trying to ensure that native plants are not crowded out by non-native species. A number of new plants have invaded the park. Some of these—classified as noxious plants—are particularly aggressive and, because they did not evolve in this environment, do not have natural controls.

Left to their own, noxious plants will quickly crowd out and take over the habitat of native plants. Indeed, it is not uncommon to see fields of sweet clover, spotted knapweed, and leafy spurge in areas that were formerly pristine. The ubiquitous wooly mullein raises its tall stalks wherever soil has been disturbed.

Crews in the park are small, though, so volunteers do a lot of the weed pulling. On June 29, 2004, for example, the National Park Service Natural Resources Divisions from Fort Collins and Denver, who were here for their Annual Service Day, used a combination of shovels and hand pulling to eradicate exotic plants. The primary target plants were five: musk thistle, woolly mullein, yellow sweetclover, houndstongue, and Dalmatian toadflax. A total of 110 volunteers managed exotic species on approximately 25 acres throughout the park. Members of the park's Natural Resource crew led groups of twelve volunteers to different sites throughout the park that were in need of exotic plant management.

Dalmatian toadflax, yellow sweetclover, and woolly mullein were mostly pulled by hand, while the musk thistle and houndstongue were dug up to ensure that the roots of these plants were removed. Each group was provided with picture ID cards of each exotic plant being targeted, including information about the plant's biology, ecology, and various management strategies. Park staff are very grateful for all the help provided by this great group of volunteers!

If you or your group would like to volunteer to help us battle invasive weeds, please visit our Volunteer page for more information.