Glacier FarmMedia — Manitoba rancher Herman Bouw was casually perusing a gardening seed catalogue when a particular ornamental grass item caught his eye.
The plant was listed as “squirrel tail grass,” but Bouw thought it looked awfully similar to a species with a more cursed name on the Prairies. A comparison of scientific names confirmed his suspicion. The catalogue was selling foxtail barley, a notorious weed and menace to his cattle.
“I kind of lost it,” Bouw said.
He is familiar with the risk this weed poses to his operation. The stiff, sharp awns of foxtail barley can lodge like slivers in the mouths of livestock, causing infections.
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The plant is a common sight in ditches and saline areas all over Manitoba — but to Bouw’s way of thinking, there’s no need to propagate more.
“We don’t need to help the devil,” he said.
Foxtail barley is also a Tier 3 noxious weed in Manitoba, which requires it to “be controlled if the weed’s uncontrolled growth or spread would have a negative impact on the economy, the environment or the well-being of residents nearby,” according to a Manitoba Agriculture fact sheet.
Under that classification of the Manitoba Noxious Weeds Act, squirrel tail grass (a.k.a. foxtail barley) can’t be deliberately grown in Manitoba, said Kim Brown, weed specialist with Manitoba Agriculture.
Historical invaders
There’s a lengthy history of noxious or invasive ornamental plants, some of them imported for their beauty, only to spread past the garden bed and into a problem.
“Over 60 per cent of Canada’s invasive plants were intentionally introduced over the last 150 years based on their value for food, medicine, ecosystem services, as well as aesthetics,” says the Canadian Council on Invasive Species.
The oxeye daisy, a delicate, white-petaled flower with a yellow centre often seen along roadsides, is one example. It could be mistaken for a native wildflower but it isn’t. It was likely introduced from Europe in the 1800s through contaminated grass seed, says the Manitoba Invasive Species Council website.
This flower still appears in some “wildflower” seed mixes, the council added.
The more infamous purple loosestrife was introduced in a similar way, either through contaminated seed, soil used for ship ballast, or deliberately by beekeepers in the 19th century, according to the national Invasive Species Centre headquartered in Ontario.
That plant can produce as many as two million seeds in a growing season, the centre added, and has spread across almost every Canadian province and U.S. state, where it can choke out native plants.
Baby’s breath, a standard in many floral bouquets, is a Tier 2 noxious weed in Manitoba. The Manitoba Master Gardener Association also warns against planting periwinkle (vinca), queen anne’s lace, yellow clematis, common barberry and certain barberry hybrids, valerian, and many more — all because they’re noxious or invasive.
Taking action
If a seed company or greenhouse is selling plants that fall under Manitoba’s Noxious Weeds Act, the province may ask them to knock it off.
“They just may not know,” Brown said.
West Coast Seeds, in whose catalogue the foxtail barley appeared, is based in British Columbia. Foxtail barley doesn’t appear on that province’s noxious weeds list, nor does it feature on federal lists of noxious weeds or invasive plants regulated by Canada’s Plant Protection Act and Seeds Act.
West Coast Seeds did not respond to a request for comment.
(Editor’s Note, April 5, 2024: While listed in the company’s print catalogue, squirrel tail grass seed is no longer listed for sale on West Coast Seeds’ web site.)
Not all invasive species are federally or provincially regulated so there’s no legal way to stop garden centres from selling them.
“I think a lot of our retailers do a great effort of trying to do the research, but they have capacity limitations … they’re trying to run a business,” said Gabby Nichols, project co-ordinator with the Canadian Council on Invasive Species.
The council has developed a voluntary code of conduct for greenhouses and seed companies to help develop awareness of invasive species and prevent their introduction or spread.
Besides discouraging the growth or sale of invasive plants, the code promotes suitable alternatives. It also suggests labelling plants correctly, by both common and scientific name, and working with regional experts to keep informed on regional invasive plants.
The council has also developed resources to foster gardener awareness.
Gardener beware
For gardeners, lists of noxious and invasive plants are available through resources published by the Manitoba Master Gardener Association, the Invasive Species Council of Manitoba, the Canadian Council on Invasive Species, or provincial and federal noxious and invasive lists.
Gardeners should also approach online purchases of plants or seeds with caution, the Invasive Species Council of Manitoba says. As in the case of foxtail barley, plants native or benign in one area may be noxious in another.
The council suggests checking the scientific (Latin) name of plants when perusing the greenhouse or seed catalogue, and avoiding plants without that information.
Gardeners should also read the ingredients in wildflower mixes because they can contain invasive plants, and should be cautious when buying exotic plants.
“Ornamental plants imported and sold under this category have become some of our worst invaders,” the council reports.
