A volunteer with the Central Kootenay Invasive Species Society works on a species inventory on City of Nelson land in the summer of 2021, with knotweed on the right and tansy in the centre of the photo. Photo: Submitted

A volunteer with the Central Kootenay Invasive Species Society works on a species inventory on City of Nelson land in the summer of 2021, with knotweed on the right and tansy in the centre of the photo. Photo: Submitted

Invasive species: Nelson to increase penalties and education

New bylaw will be ready later this year to combat destructive species

Should the penalties for failing to remove invasive species from Nelson private property be stiffer? How thoroughly are the present regulations enforced?

Is the city doing enough to control weeds on municipal property?

These questions arose at a Feb. 22 meeting at which Nelson City Council heard a presentation by Erin Bates, executive director of the Central Kootenay Invasive Species Society (CKISS).

An invasive animal or plant species is one that causes economic, environmental or social harm in an environment where they are not native. They are known for destroying complex ecosystems by crowding out all other species.

Invasive plants clog waterways, destroy natural ecosystems including rare and endangered species, destroy natural wildlife and fish habitat, increase wildfire danger, increase soil erosion, degrade water quality and decrease land values.

In 2021 the CKISS did a baseline inventory of all invasive plant infestations in the city. The resulting map, which Bates presented to council, shows 32 infested sites located within the city limits but not on private property. These include the city’s public works yard, its gravel storage yard, and Nelson Hydro’s generating facility. The latter hosts a serious infestation of Scotch broom, Bates said.

The city intends to develop a five-year management plan jointly with CKISS starting this year. It will update regulations and enforcement as well as increase training for city staff and the community.

Bates recommended using the District of Squamish’s bylaw as a model. That municipality has prohibited the sale, spread, and cultivation of invasive species and instituted a penalty of $10,000.

Nelson’s current penalty for not controlling invasive species is $250 and it has no rules against selling them.

Invasive plants such as flowering rush, periwinkle, English ivy, yellow archangel, mountain bluet, and yellow flag iris are often spread by gardening and water landscaping.

Bates said Nelson is moving in the right direction and is far ahead of many municipalities in the province.

She suggested incentive programs such as a subsidy for landowners to eradicate weeds on their properties to offset the onerous cost of hiring a herbicide contractor.

The most high-priority species for eradication in Nelson is knotweed. It’s the worst invasive species worldwide, and Bates said eradicating it from Nelson should be an immediate goal. The removal of invasive species is a goal stated in Nelson’s Official Community Plan.

Knotweed can grow through concrete and reach several metres in height. It can damage concrete walls, pavement, bridge and building foundations, drainage works, and flood prevention structures.

Bates said knotweed is followed in destructiveness in the Kootenays by heart-podded hoary cress, bighead knapweed, blueweed, teasel, yellow iris, cutleaf blackberry, Scotch broom, hoary alyssum, and common tansy.

Eradication of invasive species on city property only goes so far, she said. Private property owners need to act as well.

“It does not matter if you manage it on property A if it is still on property B. Long-term management suffers, so owners have to co-operate to manage their sites effectively.”

City parks and trails should be a priority because of the potential spread by people and dogs, she said.

Small areas of invasive species can be eradicated by hand or mechanical means but with some species, such as knotweed and tansy, these methods make the problem worse and so the plants need to be treated with herbicides, Bates said.

The City of Nelson has informed the Nelson Star by email that it uses the herbicide Milestone, applied by a licensed contractor, and only for knotweed.

Meanwhile, the Regional District of Central Kootenay plans to develop a management plan for invasive species in its rural areas, and an inventory of infested sites on RDCK land will be done this year.

The second-last paragraph of this article was altered on March 1 to add the name of the herbicide.


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