The Lake Simcoe Region Conservation Authority

Riverine Flood Status
Lake Simcoe Shoreline Status
Low Water Status

Giant Hogweed

Concerned about Giant Hogweed?

What does Giant Hogweed look like?

  • Giant hogweed is an invasive plant species of the carrot family, that resembles some of our native species such as Angelica, and Cow parsnip.
  • Unlike native species, Hogweed can grow up to 5 metres tall and has an herbaceous stem (the plant dies to the ground in the Fall) that is 5 to 10 centimetres in diameter.
  • Giant Hogweed produces sap containing chemicals that can cause human skin to react to sunlight, resulting in intense burns, rashes or blisters.

I think I have it on my property. What should I do?

  • Do not touch it. Giant Hogweed poses a serious health threat. Hogweed stalks, leaves, and bristles contain a noxious sap that sensitizes skin to sunlight. The reaction can cause serious burns.
  • Report the sighting to the Invading Species Hotline at 1-800-563-7711. Note that this line is receiving a number of calls about the issue. It may take some time for them to respond to your enquiry. Please be patient.
  • Call a licensed professional if you want Giant Hogweed removed from your private property. Please do not try and do this yourself. See the links below for help with finding someone.

What is the Conservation Authority doing?

  • If you think you have found Giant Hogweed on Conservation Authority property, call us and report it, 905-895-1281 or 1-800-465-0437.​
  • Unfortunately, we are not able to help with identification or eradication on private property.

Where can I get more information?

The following websites provide more information about Giant Hogweed.

Giant Hogweed

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Cow Parsnip

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phone icon   Who to Contact 

Invading Species Hotline
1-800-563-7711 Toll free

Smartphone app:

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