Scotch Broom
Cytisus scoparius
Pea family
Where is it from?
- It is native to southern Europe and northern Africa.
- It was introduced into the United States as an ornamental, and
used later to stabilize roadcuts. Now, although responsible agencies
recognize that broom is an invasive weed,
many people have learned about it the hard way.
Where are you likely to find it?
- Scotch broom invades roadsides, other disturbed areas,
pastures and native grasslands.
- Scotch broom is widespread in the Pacific Northwest. It
occurs in California near the coast from San Francisco
north and in the foothills of the Sierra Nevada mountains.
- Broom is common along road corridors in portions of the
Redwood National and State Parks. Patches have become
established in the open grasslands on Howland Hill and in
the Bald Hills prairies.
What makes it a "BAD" plant?
- Scotch broom is a prodiguous seed producer. The seeds have hard
coats enabling them to survive in the environment for up to 80 years.
- The seeds are transported from place to place in mud stuck to
vehicles, equipment, shoes and the feet of animals.
- Seeds may be carried via runoff from roads into streams and gullies.
Then seedlings may establish along streamsides and along gully walls.
- Scotch broom forms dense brush fields over six feet tall.
- The brush fields distract from appreciation of the natural
landscapes of the Bald Hills prairies.
- The brush fields diminish habitat for grazing animals,
such as the native Roosevelt Elk.
- Areas of dense brush shade out and kill native grassland
plants in invaded areas, and favor invasion by other woody,
non-grassland plant species.
- Scotch broom is a threat to the integrity of the Bald Hills
prairie ecosystem.
How do you get rid of it?
- Pull out the entire plant, including roots. When the soil
is moist, small plants can be pulled easily by hand. Winter
and spring are good seasons to do this in California.
- Larger plants must be removed with a tool such as a Weed Wrench (tm). Be sure to
remove the entire plant. Broken stems re-sprout and are
much harder to remove for the next person. Plants can be
left where pulled.
- Well planned prescribed burns in fall can further reduce the
broom in infested grasslands:
- Dense infestations of broom and infestations in the
shade remain too moist to carry fire and will require
pulling and some time to dry prior to a successful burn.
- A head fire is likely to only burn the tops off of the
broom, and the broom will survive.
- A slow, hot, backing fire kills most of the broom. Some
plants are consumed outright, and others are scalded
around the root collar, later dying from the injury. Use
of a backing fire reduces the need for laborious manual removal.
- Prescribed burns in grass consume some broom seeds and break
the seed coats of others, allowing pathogens to enter and kill
the seeds. Still other seeds may be stimulated to germinate
so that plants can be pulled out. Over time, regular prescribed
burning may be expected to help deplete the pool of long-lived
buried broom seed in the grasslands of the Bald Hills.
- Other benefits of burning the park's native grasslands are
1) control of invading trees and 2) rejuvenation
of grassland plants by comsuming dead thatch. The newly
burned grasslands attract elk because of their greater
forage value.
What can you do to help?
- Spread the word about how this plant alters the natural scene,
displacing native vegetation and degrading habitat for wildlife.
- Discourage people from planting Scotch broom or allowing
it to grow undisturbed wherever they live and work. Since
broom will have produced many, long-lived seeds, well before
it reaches its ultimate size, people may be unaware of its
potential as a weed in cultivation.
- Report all new sightings. If in a park, contact the park
Superintendent. If in the Redwood National and State
Parks, notify the Vegetation Management branch at the
South Operations Center in Orick (707-464-6101, ext. 5282).
Tell them about the location of the plants so they can be
mapped for future work projects.
- To become even more involved in control of this and other
exotic species, sign up as a Volunteer
in Parks (VIP).
- CAUTION: Do not remove broom without permission in
writing or direction from the private land owner, manager
or, if on public lands, an agency official.
