California Invasive Plant Council

Cytisus scoparius

Synonyms: Sarathamnus scoparius, Spartium scoparius

Common names: Scotch broom; English broom; common broom

Cytisus scoparius (Scotch broom) is a perennial shrub (family Fabaceae), which grows in sunny sites with dry sandy soil, and spreads rapidly through pastures, borders of forests,  and roadsides. Cytisus scoparius can be found from the coast to the Sierra foothills. This weed crowds out native species, has a seedbank that can remain dormant for up to 80 years, diminishes habitat for grazing animals, and increases risk for wildland fires.

Cal-IPC Rating: High?

Explanation of Cal-IPC ratings

• High – These species have severe ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment. Most are widely distributed ecologically.
• Moderate – These species have substantial and apparent-but generally not severe-ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread.
• Limited – These species are invasive but their ecological impacts are minor on a statewide level or there was not enough information to justify a higher score. Their reproductive biology and other attributes result in low to moderate rates of invasiveness. Ecological amplitude and distribution are generally limited, but these species may be locally persistent and problematic.
• Alert – An Alert is listed on species with High or Moderate impacts that have limited distribution in California, but may have the potential to spread much further.
• Watch – These species have been assessed as posing a high risk of becoming invasive in the future in California.

CDFA Rating: -*?

Explanation of CDFA ratings

• A – A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment.
• B – A pest of known economic or environmental detriment and, if present in California, it is of limited distribution.
• C – A pest of known economic or environmental detriment and, if present in California, it is usually widespread.
• D – An organism known to be of little or no economic or environmental detriment, to have an extremely low likelihood of weediness, or is known to be a parasite or predator.
• Q – An organism or disorder suspected to be of economic or environmental detriment, but whose status is uncertain because of incomplete identification or inadequate information.
• * – An asterisk next to the rating indicates that a plant is included in the CCR Section 4500 list of California State Noxious Weeds.
• -* – This plant is included in the CCR Section 4500 list of California State Noxious Weeds, but is otherwise not rated.

More details

Assessment(s)

Cytisus scoparius Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.

Species ID Card

Invasive Species ID Card - To support field identification of early detection species, Cal-IPC has designed a set of Species ID cards that can be downloaded, printed double-sided, and trimmed to size.

Weed Management Notes

• Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.

Cal-IPC Newsletter Articles

• Weeds and climate resilience in Sierra meadows. Brusati, Elizabeth; Johnson, Doug. Vol 24, Issue 1
• Scotch broom gall mite: a new partner in broom management . Oneto, Scott. Vol 23, Issue 3
• Weed biological control agents approved for California. Pitcairn, Michael J.; Smith, Lincoln; Moran, Patrick. Vol 22, Issue 1
• Wildland weed news. Cal-IPC. Vol 20, Issue 4
• Prioritizing Regional Response to Invasive Plants in the Sierra Nevada. Brusati, Elizabeth; Morawitz, Dana; Powell, Cynthia. Vol 19, Issue 2
• Interview with Cal-IPC co-founder Carla Bossard. Darin, Gina. Vol 18, Issue 4
• Nevada County Scotch Broom Challenge. Lorenson, Lynn. Vol 18, Issue 2
• Recommended action on invasive ornamentals. Cal-IPC. Vol 14, Issue 1
• Don’t sell a pest: A new partnership to prevent plant invasions through horticulture. Connick, Sarah; Gerel, Mike. Vol 13, Issue 2
• Scotch broom lopping trial. Taylor, Mike. Vol 13, Issue 1
• An army of one: One man’s fight against broom in Tilden Park. Richardson, Brianna. Vol 12, Issue 3
• Fighting weeds in the Tahoe basin. Donaldson, Sue. Vol 11, Issue 2
• International broom initiative: A comprehensive broom and gorse biological control effort. CalEPPC. Vol 09, Issue 2
• Richmond weed abatement ordinance. . Vol 07, Issue 1
• Fort Ord readies the troops for war – on weeds!. Fry, Virginia. Vol 06, Issue 1
• Highways as corridors of dispersal. Madison, John. Vol 04, Issue 1
• Marin supervisors establish policy against non-natives. Griffith, Quentin. Vol 03, Issue 2
• Exotic pest plants of greatest ecological concern in California September 1994. Cal-IPC. Vol 02, Issue 4
• California Exotic Pest Plant Council draft list exotic plants of greatest concern October 1993. CalEPPC. Vol 01, Issue 4

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

• Biological control agents of weeds in California: Overview of rearing, releases, and monitoring by the CDFA Biological Control Program. Moran, Patrick (2023)
• A test of the herbicide Weed Slayer for the control of invasive plants. Thomas, Don (2020)
• The role of public gardens as sentinels of plant invasion. Culley, Theresa; Dreisilker, Kurt; Ryan, Clair; Landel, Hans; Cavallin, Nadia; Arcate Schuler, Jessica; Shultz, Brittany; Gettig, Roger; Havens, Kayri (2020)
• Development and persistence of soil impacts following Scotch broom invasion. Grove, Sara; Parker, Ingrid; Haubensak, Karen (2018)
• Testing efficacy of control methods of the invasive shrub Cytisus scoparius in forest habitat of the Pacific Northwest. Haubensak, Karen A.; Parker, Ingrid M.; Grove, Sara; Kimitsuka, Stephanie; Foster, Jeffrey R.; Benson, Nancy F. (2010)
• Genetic identity and phylogenetic relationships of invasive brooms in California. Kleist, Annabelle; Jasieniuk, Marie (2009)
• Control of Scotch broom (Cytisus scoparius). Oneto, Scott; DiTomaso, Joseph M.; Kyser, Guy B. (2005)
• Partnering to prevent invasions of plants of horticultural origin. Connick, Sarah; Gerel, Mike (2004)
• A decade of dune restoration at the Lanphere Dunes. Pickart, Andrea (2003)
• Getting the job done: Working within the regulatory environment at Lake Tahoe to manage weeds. Donaldson, Susan; West, Wendy; Taylor, Kirk (2003)

Other Cytisus scoparius Information

• Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.
• CalPhotos - Images of plants taken mostly in California.
• Calflora - Distribution map and records of this species in California.
• CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
• EDDMapS - Distribution of this species in North America.
• Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
• USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.

Additional photos