Giant Hogweed has not yet appeared in Manitoba, however there are concerns the invasive species could eventually make its way here. Giant Hogweed is native to Asia and brought over to Canada as a horticultural plant. It has now established itself in British Columbia and Ontario.
"It's very invasive, so it displaces native species. It's a perennial, it's quite prolific spreading with seeds, and so it does take over," explained Jeanette Gaultier, a weed specialist with Manitoba Agriculture. She added it isn't typically a threat to crops.
To make matters worse however, Gaultier added that the sap of Giant Hogweed contains toxins that cause extreme rashes and blisters if people get it on their skin.
And while her department does get reports of suspected cases of the invasive species, Gaultier said it hasn't been confirmed in Manitoba to date. She noted that last year they were called to a report in the Whiteshell area but the weed turned out to be Cow Parsnip, a cousin of Giant Hogweed and native species to Manitoba. She admitted however, that if Giant Hogweed were to appear in Manitoba, the Whiteshell would be a likely place due to it's close proximity to Ontario.
"Both Cow Parsnip and Giant Hogweed are in the carrot family of plants, so related to parsnips and carrots, but they're a large plant and they typically like to grow in wetter areas."
Gaultier added that the two do look alike.
She noted that the leaves of Cow Parsnip are not as deeply lobed as Giant Hogweed, and added that her department also uses the seeds of the plant to diagnose what species they are looking at.
Gauliter added that Cow Parsnip isn't typically a problem in Manitoba and typically grows in wetter areas like ditches.
"Really, it's not a problem, it's not growing in pastures or in yards."
Meantime, she said there is another invasive species that we should be worried about. It's called Wild Parsnip and is also a cousin to Cow Parsnip and Giant Hogweed.
"Unlike the other two, it actually has yellow flowers that grow in clusters that look a little bit like umbrellas," explained Gaultier.
She added the plant, which has been problematic in Ontario, is blooming is right now.
"We've always had some here, again in the Whiteshell area, but over the last few years I think because it's been so wet, we've definitely seen that it's been spreading."
Gaultier noted Wild Parsnip has recently been reported in public areas around Selkirk, St. Malo and Altona.
Meantime, the Invasive Species Council of Manitoba has designated August 2017 as Invasive Species Awareness Month in Manitoba.