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Class B Noxious Weed

Gorse
Ulex europaeus
 

Gorse flowers up close


Plant family: Fabaceae
Year listed:
Native to: Europe

Why is it a noxious weed?

Gorse forms vigorous stands that grow outward, crowding out all other vegetation causing a considerable loss of grassland habitat. If forms a center of dry dead vegetation. It has a high oil content that poses a serious fire hazard.

How would I identify it?
General Description: Gorse is a perennial, evergreen shrub ranging from 3 feet to over 10 feet tall. 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.

Leaves:

  • trifoliate, thin leaflets
  • as leaves mature they become spiney
  • spines are also in the leaf axils

Flowers:

  • shiny yellow
  • pea like
  • 1/2 to 3/4 inch long
  • clustered near ends of branches

Stems:

  • erect, angular

Line drawings are taken from 1,000 Weeds of North America, copyright of XID Service, Inc and used with permission. Permission granted by the author.

How does it reproduce?

Gorse reproduces primarily by seed, but it can also spread vegetatively.

Where does it grow?
Gorse can be found in open areas, roadside, riparian areas, and grasslands.

What is the distribution in Washington State?

Click on map to enlarge.
  • Gorse has been documented in Thurston, Pierce, King, Jefferson, Grays Harbor, Lewis, Pacific, Snohomish, San Juan, Skagit, Wahkiakum and Island counties.
  • Distribution map based on 2003 data.

How do I control it?

General control methods: Gorse control should be done in two stages. First stage is to get control of established plants. Second, 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.

Cultural: Cultivation and establishing competitive pasture species, forest trees or other crops helps resist
gorse invasion as well as other weeds.

Herbicide: Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

Mechanical: Hand pulling, digging may be an option for small infestations, but the entire plant must be removed since Gorse can resprout. 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.

Biological: Goats are a cost effective control method for Gorse seedlings. Chickens eat Gorse seeds, through the digestion process the seeds are destroyed. The gorse weevil (Apion ulicis) was released in Washington in the mid-1960’s.

Are there plants that may be confused with Gorse?
Because of the yellow pea like flowers and shrubby habit; from a distance Gorse may be mistaken for Scotch broom (Cytisus scoparius), a Class B noxious weed in Washington or Spanish broom (Spartium junceum), a Class A noxious weed in Washington. The obvious spikes distinguish Gorse from these other species.  If you need help with plant identification, please contract  your county noxious weed coordinator.

 

For more information
For more information, download our Written Findings.

 

More Photos-Click photo to enlarge
Feel free to download, or contact us to receive high-resolution JPEG or TIFF formats
Gorse infestation
Gorse pasture infestation. Gorse stem with pocket knife for size reference of spikes. Gorse flowers and stems up close.
Photo courtesy of Thurston County Noxious Weed Control.

 Last updated October 01, 2008