Yellow toadflax is a member of the Figwort family and is sometimes called common toadflax or butter and eggs. It was introduced from Europe as an ornamental and has now become a serious problem to rangeland and mountain meadows. It is a perennial reproducing from seed, as well as from underground rootstalk. The flowers are bright yellow with deep orange centers that resemble the snapdragon. Yellow toadflax does well in all types of soils. Its displacement of desirable grasses not only reduces ecological diversity, but also reduces rangeland value and can lead to erosion problems. Because of its early vigorous growth, extensive underground root system, and effective seed dispersal methods, yellow toadflax is difficult to control.

Comment: An extremely aggressive weed infesting many areas of Pitkin County including Aspen, Independence Pass, Ashcroft, the Frying Pan drainage, and a small area of Snowmass Village.

Biological controls: One insect species Calophasia lunula a defoliating moth has been released on yellow toadflax. It may defoliate up to 20 percent of the leaves.

Chemical controls: For additional information contact your local city, county or town natural resource office. (See section VII for phone numbers.)

Cultural controls: Attempt to maintain competitive communities of desirable species. Re-seed any open ground with native perennial grasses to prevent invasion by other weed species.

Mechanical controls: Digging and pulling where feasible can provide effective control of toadflax if conducted annually for 10 to 15 years.

Education: The key to yellow toadflax management and other escaped ornamentals is to create an awareness among homeowners, nurseries, landscapers, and landscape architects that yellow toadflax is a noxious weed and therefore should not be specified in plantings, sold in nurseries or planted in home gardens or large-scale landscape projects.

Locations of Infestations of Yellow Toadflax on Roads and Open Space in Pitkin County