Spanish Broom
Spartium junceum
Washington State Classification
Class A — Eradication Required Statewide
Like Scotch broom, its close relative, Spanish broom can dominate disturbed areas where it can out-compete native plants and alter soil nutrients.
Quick Reference
Identification
Growth Habit
Spanish broom is a perennial, evergreen shrub with round, green stems that are leafless for much of the year. It has bright yellow, irregularly shaped flowers. Shrubs can reach a height between 6 to 10 feet.
Leaves
Leaves are alternate and lance-shaped. They are less than 1 inch long, smooth on top and with long hairs on the leaf underside. Leaves only appear between February and early June.
Flowers
Flowers have an irregular shape, typical of flowers in the pea family (Fabaceae). They are bright yellow, about 1 inch long, and fragrant. Flowers grow in clusters at the end of stalks and the bloom time is typically between July and early frost.
Fruit & Seeds
Fruits are hairy seed pods, flat and linear, up to 3 inches long.
Impact
Like Scotch broom, its close relative, Spanish broom can dominate disturbed areas where it can out-compete native plants and alter soil nutrients. It does not provide good forage for wildlife and mature stands are noted to be a fire hazard in California.
Ecology & Spread
Habitat
Its high tolerance to drought and ability to produce nitrogen allow this shrub to grow in sunny, dry, areas with poor, often rocky soil. Like Scotch broom, it is typically found in disturbed areas including eroded slopes, vacant lots, and roadsides. Please click here to see a county level distribution map of Spanish broom in Washington.
Spread Mechanisms
Reproduction
Spanish broom reproduces primarily by seed. One plant can produce between 7,000 to 10,000 seeds in just one growing season. Seeds can remain dormant for at least five years, although broom seeds have been shown to survive for over 25 years.
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Control Methods
Mechanical
- Small plants and seedlings can be effectively controlled through hand hoeing. Hand-pulling can be effective when shrubs are still small and the entire root structure can be removed. Otherwise, the root fragments will re-sprout new plants. The best time to hand-pull is between July and September, especially when the soil is dry. The stems of large shrubs can be cut; however, re-sprouting will occur unless the cut stump is treated with herbicide.