Why Is It a Noxious Weed?
Gorse forms vigorous stands that grow outward and crowd out all other vegetation causing a considerable loss of grassland habitat. Because it forms a center of dry dead vegetation and has a high oil content, it is a serious fire hazard.
How would I identify it?
Gorse is a perennial, evergreen shrub able to grow over 10 feet tall. It is shrubby with stout and upright spreading branches with angular stems and a terminal thorn. The plant habit is dense, sometimes 30 feet in diameter, with a center of dead foliage.
Flowers are shiny yellow and pea-like. They are 1/2 to 3/4 inch long and clustered near ends of branches.
Leaves are trifoliate—having 3 thin leaflets. As they mature they become spiny. Spines are also in the leaf axils.
Stems are stiff and angular with branches maturing from green to brown.
Fruit Seed Description
The seed pods are hairy, ½ to ¾ inch long, and brown when ripe. The pods burst and scatter seeds for several feet. The seeds are smooth and shiny, olive to brownish.
May Be Confused With
It may be mistaken for Scotch broom (Cytisus scoparius), a Class B noxious weed or Spanish broom (Spartium junceum), a Class A noxious weed. The obvious spikes distinguish gorse from these other species. For help with identification, contact your county noxious weed coordinator.
Where does it grow?
Gorse can be found in open areas, roadside, riparian areas and grasslands. Please click here to see a county level distribution map of gorse in Washington.
How Does it Reproduce?
Gorse reproduces primarily by seed, but it can also spread vegetatively. Its seeds can remain viable in the soil for over 30 years.
How Do I Control It?
General Control Strategy
Gorse control should be done in two stages. The first stage is to get control of established plants. The second stage is to control new plants from the existing seed bank. The most effective control program usually includes a combination of herbicides and cultivation or mowing.
Hand pulling or digging may be an option for small infestations, but the entire plant must be removed since gorse can re-sprout. Chopping, cutting or mowing is an option for flat areas. Repeated mowing may be necessary to deplete root reserves.
Cultivation and establishing competitive pasture species, forest trees, or other crops help resist gorse invasions as well as other weeds.
Goats are a cost effective control method for gorse seedlings. Chickens eat gorse seeds, and through the digestion process the seeds are destroyed.
For More Information
See our Written Findings for more information about gorse (Ulex europaeus).
Thurston County NWCB Fact Sheet on gorse
King County NWCB Fact Sheet on gorse
Jefferson County NWCB Fact Sheet on gorse
Pierce County NWCB Fact Sheet on gorse
Control Options for gorse from King County NWCB