Description:
Gorse is a perennial, evergreen shrub ranging from 3 feet to over 10 feet tall. Seedlings are compact, with trifoliate leaves and thin expanded leaflets typical of legumes. With plant maturity, the leaves develop an awl-shape (spinelike). Well-developed branch spines also grow in the leaf axils. Overall, gorse plants are shrubby with stout and erect spreading branches with angular stems and a terminal thorn. Branches mature from green to brown. The plant habit is dense, sometimes 30 feet in diameter with a center of dead foliage. The shiny yellow, pea-like flowers are 1⁄2 to 3⁄4 inch long, with an ovate banner (upper petal), oblong wings (lateral petals) and keel (lower, united petals). The wings are larger than the keel. The calyx is pubescent and deeply two-lipped. The upper lip is 2-toothed and the lower lip is 3-toothed. The ten stamens are monadelphous. The flowers are solitary or racemous, and clustered at branch tips. The seed pods are hairy, 1⁄2 to 3⁄4 inch long, and brown when ripe. The pods burst and scatter seeds for several feet. The seeds are smooth and shiny, olive to brownish. The root system consists of a taproot, lateral roots and adventitious roots (Hoshovsky 1989; Parker and Burrill 1991).

• Mechanical: Hand pulling - effective on seedlings and plants up to 1 meter or so tall, and before seed production. Seedlings are easiest to remove after rain, when the whole root system is removed. Hand hoeing – effective when gorse is growing with beneficial vegetation nearby. Hoeing, and cutting off the top of plants will expose them to the sun, drying them out. Cutting – before seed production will prevent further dispersal, but the plants will resprout from the stump. Cutting is a necessary step when working with large plants, to remove the above ground portion. Hand-digging – effective on small infestations, is one way to control a plant the capability to resprout from the roots. Chopping, Cutting or Mowing – an option for flat areas. Several mowings may be necessary to deplete root reserves; if only one cut, it is recommended to use before flower production. Cutting is recommended before herbicide application. A cut gorse plant will resprout from the crown in greater density if herbicides are not applied. (Hoshovsky 1989).
• Biological: Goats are cost-effective as a control option on gorse when used against seedlings or on regrowth less than 4 inches high. Goats will defoliate twigs and bark from mature stands of gorse. After a two-year period there was a significant reduction in gorse crowns (Hill 1949 as cited in Hoshovsky 1989). Chickens are effective in potentially reducing the seed bank in mature stands of gorse. The seeds are digested and destroyed, and chickens grazed back the vegetation in areas of one acre or less (Andres 1979 as cited in Hoshovsky 1989).
• Herbicide: Several herbicides are recommended for gorse control, including glyphosate, Crossbow, Tordon, Escort and Banvil, to name a few. For site specific control recommendations, please refer to the most recent version of the PNW Weed Control Handbook referenced in the bibliography (Williams et al. 2000). Refer to the State Noxious Weed Control Board site

For More Information:
Detailed information about Gorse is available at the Washington State Noxious Weed Control Board Web Site.