Scotch broom is a Class B noxious weed in Washington State. As you may already know, Scotch broom is an incredibly invasive flowering shrub throughout Hood Canal and Western Washington. Because of its agressiveness, it can spread qucikly, creating dense stands. These infestations can degrade important wildlife habitat. Scotch broom is listed on Washington’s quarantine list, which prohibits the transportation and purchase of the plant or its seeds within Washington.