Invasive Knotweed Regional Reporting System launched in the Capital Region

Protect Against Invasive Species - Scotch Broom

Why control Scotch broom

Broom (1) Scotch broom is an invasive woody shrub.  It was first introduced to southern Vancouver Island in the 1850's, and now grows prolifically throughout southwestern British Columbia.  Broom is most often found in open areas such as meadows, forest clearings, roadsides and hydro corridors.
 
Broom changes the chemistry of the soil around it so that other plants can't grow there.  It spreads and grows quickly, creating dense monocultures.  Broom is a particularly serious threat to the biodiversity of the Gulf Islands, eliminating native plant communities that birds, butterflies and other
animals rely on for habitat.  Broom is also particularly flammable, increasing the fire hazard of a property.

 
What you can do to help

You can remove broom!  Replacing broom with native species gives our native ecosystems a chance to fight against this highly invasive species.

Before you begin

Prioritize where you are going to work.  A mature broom plant can produce more than 10,000 seeds and distribute them as far as 20 feet away.  First, keep uninfested land free of broom, by removing new and isolated plants or patches.  Then, move onto large dense broom infestations by starting at the edges and working towards the centers of infestations.  Removing those mature plants producing seeds also help contain infestations. Broom (2)

Time your work so that the least amount of soil damage occurs.  Broom seeds germinate well in disturbed areas, especially when they have very few native plants to compete with.  The best time to remove broom is when the soil is moist - between November and February.  This timing also brings the least amount of disturbance to any underlying native vegetation.  Don't plan your work when broom seeds are ripe - disturbing the plant will help spread the seeds to new, uninfested areas. 

Be ready to replace broom with native vegetation.  Bare, exposed soil is prime breeding ground for more broom.  Rapidly growing native or non-invasive plants will help shade out broom seedlings that might spring up after you've removed a broom monoculture.

Pull or cut

Pull small broom plants by hand when the soil is wet.  Many local organizations loan broom removal tools specially designed for broom pulls.
 
Cut broom plants greater than a half inch at the base, or plants that can't be pulled without bringing up large clumps of soil.  Prevent cut broom plants from re-growing by either cutting the plant just below the ground surface or stripping the bark from broom stumps to below soil level.  The
Broom (3)
best time to cut a broom plant is when it is in bloom or just before - the plant will have used all its energy to produce flowers and will hopefully become drought-stressed as summer sets in.  Try not to cut broom once it has produced seeds - you'll likely help the plant spread its seeds with the disturbance.

 

Dispose of broom

Check with your regional district for information on how residents can dispose of invasive species.  Composting broom is risky; seeds might not break down and may contaminate your compost.  Pulled plants left on-site may kill any vegetation underneath, and become a fire hazard.

Restore the site

Broom can re-establish quickly on bare soil.  Quickly restore sites where broom has been removed.  Alternatives to broom can include native grasses, Oregon grape, red flowering currant and Douglas fir.

It is important that you return regularly to areas that you have removed broom infestations to remove the flush of seedlings that will germinate with the new exposure to light.  The good news is that these new seedlings are the easiest to remove, usually by hand in a simple walk-about of the land.  With regular follow-up, you should be rewarded with a beautiful array of native herbaceous species likely to sprout up in the newly restored area. 

Information adapted from the San Juan County Noxious Weed Control Board and Pender Islands Conservancy Association.

For more information and helpful tips

A number of local and regional conservation organizations are helping islanders control Scotch broom.  Contact your local conservancy to see if they organize broom removal events for volunteers.  For more information about Scotch broom and best practices for removing this plant from your land, visit:

Page last updated: 10/02/16
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