Giant Hogweed is an Asian plant that was brought to North America about a century ago and is now spreading throughout southern Ontario.
It can be hazardous to human health. Giant hogweed sap will make a person's skin extremely sensitive to sunlight. Contact with a plant, followed by exposure to the sun, can cause severe burning and blistering. If sap gets into your eyes, it can lead to blindness.
If any sap touches your skin:
- wash the affected area immediately with soap and water
- keep the affected area out of the sun
- see your doctor if you have a reaction
Watch out for lookalikes
Giant hogweed is part of the carrot family and can sometimes be confused with other common plants such as cow parsnip and angelica. This giant hogweed fact sheet compares giant hogweed to other species.
Giant hogweed fact sheet (PDF)
Giant hogweed poster (PDF)
Ontario's Invading Species Awareness Program (Link to website)
Information provided by Grand River Conservation Authority