Mustard invades St. Albert

City residents should be on the lookout for a mustard menace this month as the province brings in major changes to its weed control act.

The new Weed Control Act is expected to become law May 1, says Jim Broatch, pest management specialist with Alberta Agriculture, and it will add a host of new plants to the province's destroy-on-sight list.

Among those invasive weeds is the garlic mustard — a spade-leafed green plant recently spotted in the Forest Lawn Ravine.

Kevin Veenstra, the city's tree and pest control foreman, says he stumbled across the weed last week while working in the area. It's currently the only green plant on the forest floor, he says, and it's already taken over half the ravine. "By the looks of the infestation, I'd say it's been here for a while."

Left unchecked, Veenstra says, this plant could easily displace all native species throughout this ravine and the Sturgeon River. "All the native forest will become dominated by garlic mustard." The infestation is already so big that he plans to skip hand-pulling and jump directly to pesticides — he'll spray the weeds with Roundup next week.

Weed shakeup

Invasive plants are introduced species that displace native plants, says Virginia Battiste of the Alberta Invasive Plants Council. Such plants harm riparian zones, wildlife, and people. Many are garden plants that escape and run wild.

The old weed act had three categories of weed, Broatch says: nuisance ("control if you like"), noxious ("stop it from spreading"), and restricted ("destroy on sight").

The previous version focused on a small number of agricultural weeds, Broatch says. The new one brings in parks and natural areas, and takes a more preventative approach. "The more weeds we can prevent getting established in Alberta, the better."

The act greatly expands the list of restricted weeds, which are now called "prohibited noxious" weeds. While the old list had seven plants, the new one has 46. City staff will be obliged to destroy these plants on sight.

These are plants that are in or poised to come into Alberta in the near future, Battiste says. "If we aren't careful and aren't diligent, they're going to become the same problems here as they are in other jurisdictions." Store owners and gardeners should avoid growing these plants. Her organization and the province have planned an education campaign to teach people how to spot these invaders.

The act also expands the list of noxious weeds, adding St. Albert pests such as burdock. It eliminates the nuisance category altogether since those weeds are too widespread to control, Broatch says.

St. Albert's new invaders

Veenstra knew of four weeds that the city would have to destroy under the new act: garlic mustard, purple loosestrife, flowering rush, and Himalayan balsam.

St. Albert has been pulling purple loosestrife from the Sturgeon for years, Veenstra says. He's not sure where the tall, magenta-flowered plant is coming from, but notes that it used to be popular in gardens.

The flowering rush is a grassy aquatic plant with an umbrella-like cluster of pink flower heads on top, he says. These plants have been spotted near the bridge at St. Albert Trail.

Himalayan balsam is also known as policeman's helmet, according to the Alberta Invasive Plant Council, since it has pink flowers that are shaped like a British police helmet. It spreads quickly using explosive pods that can launch seeds up to six meters away. Veenstra says they've been spotted near outfalls in Riel and Braeside.

The new weeds will mean more work for Veenstra's crews, he says, but he was sure they could handle it. "We've always taken care of all those weeds anyhow." His department is planning an expanded weed awareness campaign this summer that will feature public weed pulls.

Anyone who spots an invasive weed is asked to call public works.

The complete list of weeds can be found at www.stalbertgazette.com. For details on the new weed act, visit www.invasiveplants.ab.ca.