The Curse of Broom

By Janis Ringuette

Many Victorians appreciate the bright yellow blossoms and distinctive scent of Scotch broom (Cytisus scoparius). Some might agree with St. Barbe, who wrote eighty years ago that the “main glory” of Beacon Hill Park was “acres and acres of broom that in spring and early summer are a blaze of gold.”

Those who value native habitats have a different perspective. They know broom is a foreign invader advancing relentlessly across our landscapes, a noxious weed crowding out native species and destroying open meadows. Broom has been a disaster for Garry oak ecosystems. A provincial government publication explained: “Rapid spread of Scotch broom has...replaced native plants, changed soil nutrients, and dramatically altered the make-up of these ecosystems.” (Wayne Erickson, “Garry Oak Ecosystems,” 1999)

Broom patch

[Northwest Ridge broom patch.
Photo: N. Ringuette, April, 2004.]

Broom has been disastrous for butterflies, too. “Of all the alien plant species that have been introduced to the region, the most detrimental for butterflies has been an invasive, yellow-flowered shrub called Scotch Broom...[It] has spelled disaster for butterflies ever since...taking over natural meadows and crowding out most of the native flora.” (Nancy Baron and Frances Backhouse, “Rare Butterflies of Southeastern Vancouver Island and the Gulf Islands,” 1993)

Some Victoria residents believe the person who brought starlings to North America also introduced broom. This is not the case, though the general problem--introducing exotic species which then spread to the detriment to native species--is the same. It was Eugene Schieffelin who introduced eighty starlings in New York’s Central Park in 1890. By 1992, there were more than two hundred million starling descendants out-competing native birds across North America, including right here in Victoria. The person to blame for severe environmental problems caused by broom was actually a Victoria area resident. Capt. Walter Colquhoun Grant planted a few broom seeds at his Sooke farm in 1851. From there, the exotic shrub has spread like a plague throughout the region and up the Island.

Broom patches are visible today on Beacon Hill and in many other areas of the Park. The problem was far worse in the 1920's and 1930's: the entire hill was covered in dense broom growth. In 1925, the invasive shrub was so thick on the south slope of Beacon Hill that the Park Committee actually considered cutting large letters in the broom to form the words “Welcome to Victoria.” Walking through broom was so difficult two years later, the Committee directed the Park Superintendent to cut fifteen-foot wide lanes and keep them open.

During his nearly forty years as Park Administrator (1931-1970), W. H. Warren worked to reduce the overwhelming amount of broom in the Park. Each year, workers pulled, chopped, bulldozed, poisoned and burned broom. In 1946, Warren said: “We spend a considerable portion of the annual appropriation on the control of broom...if it were not so, the Park would be over-ridden with broom in a few years...”

Warren warned broom was a serious fire hazard: “Repeated bush fires in the broom have ruined the oak trees on the northeast slope of the hill.” Broom burns longer and at a higher temperature than native vegetation and this damages trees. Before white immigrants settled in Victoria, frequent fires set by First Peoples burned quickly and at a low temperature because there was no buildup of fuel and, of course, no broom. Those fires, set for hundreds of years in late summer or fall, kept meadows open, enhanced the growth of native plants and did not damage mature oaks. Today in the Park, many Garry oaks are surrounded by broom. Unless this broom is removed, fire could damage the trees.

By 1949, Warren could see great progress in his campaign to reduce the amount of broom. He said, “Fifteen or so years ago the broom occupied an area about ten times greater in Beacon Hill Park than it does now.” In 1952, he noted “wild meadowland flowers” were able to bloom again where broom cover had been removed.

Broom is hardy, persistent and successful. We can never eradicate it, but a concerted, continuing effort to reduce and limit broom growth is essential. (“Friends of Beacon Hill Park Society Newsletter,” April, 2004)