Species Information

• Scotch broom
• Cytisus scoparius (L.) Link
• USDA Symbol: CYSC4
• Oregon Noxious Weed Designation: B, T
• Pictures

Identification: Perennial; blooms April to June. Grows 3 to 10 ft tall. Evergreen shrub with many slender, erect, dark green angled branches with small, simple leaves. Abundant small, yellow, pea-shaped flowers. Easily confused with Spanish broom. Spanish broom (S. Junceum) has round stems, very few leaves, and larger yellow flowers.

Impacts: Scotch broom is a pioneer species known to displace native plant species and increase the costs of timber production. It readily invades disturbed sites, natural areas, dunes and public and private forest lands. Maintenance of rights-of-way, facilities, parkland and private property costs millions of dollars each year because of rapid growth of young plants and the plant's persistent nature. Seeds of Scotch broom are long-lived (50 years plus) and mature plants are prolific seed producers, establishing persistent seed banks requiring long-term management objectives. The largest costs attributed to scotch broom come from additional inputs needed to establish trees in commercial and public timberlands. It is estimated that Scotch broom costs Oregon $47 million dollars annually in lost timber production.

Biological Controls: Three biological control agents, a beetle, a seed weevil and a twig miner are approved for release and have been established in Oregon.

Oregon Maps of Scotch Broom Distribution

Links:

USDA Plants Database information on Scotch broom

GRIN Database information on Scotch broom

Oregon Department of Agriculture information on Scotch broom