 Scotch Broom
Cytisus scoparius (L.) Link
Family: Fabaceae
Description and Life Cycle
Scotch broom is a perennial, evergreen shrub that reproduces by seed. Mature height is
1 - 3 m tall with stiff angled, somewhat erect, dark green branches creating an irregular shape.
Many of the branches are leafless or have few leaves. Upper leaves are simple (single) while
lower are trifoliate (three parts). Forked tap roots enable it to anchor in rocky shorelines
and steep slopes. Bright yellow 2.0 cm pea-like flowers appear from early April through June.
Up to eight brown seeds, 2 - 3 mm long with shiny coats, develop within brown-black pods with
hairy margins. In the soil, seeds can remain viable for 60 years or more. Scotch broom spreads
rapidly in an open canopy along right-of-ways, trails and near streams. It is drought tolerant,
preferring infertile or rocky soils and is well adapted to windy seashore conditions. All parts
of the plant contain small amounts of toxic alkaloids capable of poisoning livestock when consumed.
As with all plants in the Fabaceae family, it too fixes nitrogen, however, the nitrogen does
not become available until after the plant dies.
 British Columbia Biological Control Agents
References
MFR staff observations and comments
Parker, B., Miller G. and L. C. Burrill. 1998. Scotch broom, Cytisus scoparius (L.)
Link. Weeds. A Pacific Northwest Extension Publication. PNW 103, reprinted October 1998.
Rees, N. E., P. C. Quimbly Jr., G. L. Piper, E. M. Coombs, C. E. Turner, N. R. Spencer,
L. V. Knutson. 1996. Biological control of weeds in the west. Western Society of Weed Science.
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