One of Ontario’s most dangerous weeds is back in Oshawa


Published July 12, 2022 at 2:03 pm

wild parsnip
Wikimedia Commons photo

Toxic plants that can cause severe burns and blistering are now blooming in Oshawa.

Wild parsnip and cow parsnip are a concern across Ontario and continue to be found along the edges of parks, open spaces, trails and roadsides, the City of Oshawa notes in a news release on July 12.

“They look like colourful wildflowers but are actually toxic plants… growth of the plants begin in the spring and lasts through early autumn,” the release states. “Wild Parsnip and Cow Parsnip are currently flowering in Ontario, including in local areas in Oshawa.”

The plant sap contains chemicals that may cause skin and eye irritation and make the skin prone to severe burning and blistering when exposed to the sun. Symptoms typically occur within 48 hours and consist of painful blisters that may result in scarring.

Both people and pets can be hurt.

Officials say people shouldn’t touch or pick the flowers from these plants.

“Please warn your children to not touch the flowers,” the release states.

The best way to avoid contact is to be aware of what the plants look like.

wild parsnip oshawa

Wild parsnip

Wild parsnip has yellow flowers that will grow up to 1.5 metres tall. The single steam of the plant is smooth featuring leaves arranged in pairs featuring sharp mitten-shaped leaflets.


Cow parsnip

To identify cow parsnip look for a 1 to 2.5 metre tall stem that has a few purple areas and deep ridges with fuzzy hairs. The plant features white round flower clusters with leaves showing similar shape to a maple leaf, or an open palm with three fingers outstretched.

For more information, visit or call the Invading Species Hotline at 1-800-563-7711.

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