John Armstrong and giant hogweed spreading along Nepewassi Lake Road. Laura Stradiotto photo Laura Stradiotto, Local Journalism Initiative Reporter

Giant hogweed, that large invasive non-native weed that can pose a threat to our health and environment, is still rearing its menacing head across Greater Sudbury and outlying areas.

John Armstrong works in Sudbury but lives on Nepewassi Lake Road in Markstay-Warren. He’s removed giant hogweed from his property a few times already, wearing all the recommended PPE – coveralls, industrial gloves, goggles, mask and boots.

The clear water sap from the weed contains toxins that can cause severe dermatitis and burns if exposed to skin and then to sunlight. Symptoms include painful blisters within 48 hours after skin exposure, and even temporary or permanent blindness after eye contact.

But giant hogweed is so darn difficult to completely eradicate, Armstrong says, pointing to a seedling on his property. If one tiny seed escapes, new growth is imminent. Each plant can produce up to 120,000 winged seeds, which can then be spread up to 10 metres by wind and be carried down streams and rivers for three days.

There are plenty more areas along Nepewassi Lake Road where the weed thrives and Armstrong worries that not all residents may be familiar with the plant that can grow up to 16 feet tall and that this unintentional ignorance could likely lead to it spreading further.

The municipality of Markstay-Warren, like the City of Greater Sudbury and other communities, follows the Provincial Weed Control Act. That means the municipality is responsible for the management and removal of invasive species that grow on its land. But if it grows on private property, it’s up to land and homeowners to remove it.

In Markstay-Warren, bylaw officers are designated to inspect any complaint regarding the potential location of hogweed on municipal property, said Kim Morris, the acting CAO/clerk/treasurer for the municipality. If the plant is indeed hogweed, the municipality will post signs to warn of the potential risk and use a third party to remove it.

In Greater Sudbury, the number of confirmed sites has greatly decreased in the last decade, thanks to the vigilance of both residents and the city, said Stephen Monet, manager of strategic and environmental planning with the City of Greater Sudbury.

“This is the first invasive species we have grappled with, starting in 2010, because of its potential toxicity.”

A number of “hotpots” in Greater Sudbury remain, but they are considered under control despite it taking some years to completely eradicate a site. Hotspots include along Atlee Street and Second Avenue near the storm ponds.

If Sudbury residents think they have the plant growing on their property, they should call 311. The strategic and environmental planning department will then assign a biologist to visit and inspect the site to determine whether the plant is indeed the invasive species.

The majority of calls received are determined not to be giant hogweed, said Monet.

There are plants that look like giant hogweed, like Queen Anne’s lace and cow parsnip, a native plant to the area that can grow up to eight feet tall and whose sap can cause similar burns. But cow parsnip is not invasive so it does not need to be removed.

However, those plants that are determined to be giant hogweed — and are on city property — will be removed by the city.

If the plant is found on private property, plant removal is the responsibility of the land or homeowner.

Another option is to pay a third party to remove the plant, said Monet.

If removing the plant on your own, there are safety precautions to follow: wear long sleeve shirt, industrial rubber gloves and eye protection. Monet said a crucial part of the process is to first remove the flower head, which contains the seeds, place it in a garbage bag and then in the sun to suffocate.

Next, in order to get rid of the plant waste, residents should call 311, about 48 hours in advance, and make arrangements with the Sudbury landfill site to drop it off at no cost.

The site requires advance notice of the drop-off because only specific areas are designated for the plant waste. Whatever you do, don’t place it at the curb with your other yard trimmings or garbage.

“It’s extremely important that people don’t take matters into their own hands and decide to dump that in the bush,” said Monet. “It’s unfortunate we have come across a couple of sites where people have dumped garden waste that contained giant hogweed in the bush and then we have to go and remove it even though it’s on Crown land.”

To learn more about giant hogweed management, prevention and removal, visit

The Local Journalism Initiative is made possible through funding from the federal government.

Twitter: @SudburyStar

By Laura Stradiotto, Local Journalism Initiative Reporter

Original Published on Jul 18, 2023 at 00:32

This item reprinted with permission from   The Sudbury Star    Sudbury, Ontario
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