by Korie Marshall

Canada Thistle threatens native species at Valemount’s Cranberry Marsh. Local youth pitched in to help / KORIE MARSHALL

Over 35 people, including local Guides, Brownies, Sparks, Junior Rangers, and other volunteers gathered at Cranberry Marsh on Sunday to hand-pull Canada thistle.

Despite its name, Canada thistle is not native to Canada, and has adverse effects on ecosystems like in Cranberry Marsh: it crowds out native species, and makes it uncomfortable to hike in shorts in late summer.

The marsh trails are popular with hikers and bird watchers. It is part of a wildlife management area (WMA), so motorized vehicles are not allowed, and proximity to waterways and sensitive species rules out the use of herbicides, so hand-pulling is the only way to tackle the prickly plants.

Volunteers pulled 12 bags of mostly small, young plants, which were marked as “invasive plant material” and taken to the transfer station for disposal. We noticed the cool and damp weather and early growth stage definitely worked to our advantage, but it will take a concerted effort over a few years to get the Canada thistle under control. “Deadheading” – removing the flower heads before the seeds spread – can also help reduce the plants that come up next year.

The weed pull was organized by Northwest Invasive Plant Council, with help from Duncan McColl, Ecosystems Biologist, Dave Rogers and Dayna Hassell of Spectrum Resources Group, and sponsored by the Fish and Wildlife Compensation Fund.