Scotch broom is an invasive ornamental and is listed in the book, "Weeds of the West" because of its invasiveness in California and Oregon. However, it is only marginally hardy in Colorado. Scotch broom is listed as a Zone 5-6 plant for hardiness, and it rarely survives through several winters. The Colorado Department of Agriculture has not listed it as a noxious weed in Colorado, and it is unlikely, unless the state has a significant warming trend, to become the problem it is on the West Coast. ***
