Common broom flowers.
Common broom. Photo Credit: Eric Coombs, ODA, Bugwood.org
Common broom seedpod. Photo Credit: Martin LaBar, Flickr
Common broom infestation.
Also known as: Scotch broom, Scot’s broom.
Chances are you’ve seen common broom. Its bright yellow flowers stand out along roads and highways throughout the Tualatin River watershed. While its flowers bring a splash of color to the landscape, its dense growth displaces native plants and desirable crops. It also creates ladder fuels in forested areas.
For a more detailed description, download the Common Broom Best Management Practices Factsheet.
|Perennial (life cycle lasts more than one year)
|Early Detection and Rapid Response species:
|Up to 12 feet (4 meters) tall
|Common broom has dark green leaves composed of three oblong leaflets. Its leaves often fall during the summer in periods of drought, leaving bare green
|Fruit & Flower Description:
|It produces a mass of bright yellow, pea-like flowers. Each flower has five petals.
It produces thousands of tiny seed pods once they have bloomed. Their seeds can remain viable in the soil for up to 80 years.
|March to June
How it spreads:
- Brooms are prolific seeders. After two or three years of growth, a single plant can produce several thousand seeds per year.
- Plants can sprout from stumps or root crowns after damage to their above ground growth.
- Common broom grows best in open sunny areas with well-drained soils.
- It can be found along roadsides, pastures, grasslands, and areas that recently experienced soil disturbance.
- Common broom grows in dense stands that outcompete native plants and crops for space and nutrients. This results in the loss of grasslands and prevents reforestation by crowding out conifer seedlings.
- It poses a serious fire hazard. Dense stands create ladder fuels that allow wildfire to spread into tree canopies.
- It produces toxins that inhibit neighboring plants from growing.
- It can cause mild poisoning in livestock such as horses and alpacas when consumed in large amounts.
What you can do about it:
- Manual: Manual treatment, such as hand pulling or digging, are options for small patches. The best time for treatment is in the spring when the ground is damp.
- Treatment must be repeated for many years because these species produce thousands of long-lived seeds and are able to re-sprout from small stems, stumps, or root crowns.
- Weed wrenches can assist with removing larger plants. If you are in Washington County, we lend these tools for free from our tool library.
- Plant material should be burned or disposed of in tied plastic bags in the garbage – not the yard debris or home compost.
Brooms are often confused with gorse (Ulex europaeus). Unlike broom species, gorse has thorny stems.
Individual brooms species have similar characteristics, but there are slight differences that distinguish each species. Visit the resources below to explore these differences.
Noxious Weed Listing:
- Pacific Northwest Weed Management Handbook: Brooms
- University of California, Weed Research & Information Center: Scotch broom
- Oregon Department of Agriculture: Portuguese broom
- Oregon Department of Agriculture: Spanish broom
- Washington State Noxious Weed Control Board: Spanish broom
- University of California, Weed Research & Information Center: Spanish broom