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Giant Hogweed

Giant hogweed can be a harmful plant and is found in scattered locations across southern Ontario. The plant can grow from four and half metres to six metres tall, with leaves reaching a span of approximately one and a half metres across.

Giant hogweed has a hollow stem with dark reddish-purple splotches and coarse white hair. Hairs are also found under the leaves. The plant produces a clear, watery sap that is found in the hairs and stem. Contact with the plant may cause skin reaction - the plant’s sap reacts with ultra violet light from the sun and blisters on the skin may result, which can lead to pigmented purple or black scars.  Contact with eyes may lead to temporary or permanent blindness.

Giant hogweed was introduced from Europe as an ornamental plant and has spread throughout the southern Ontario area. It can be found in parks, roadsides, stream banks and even backyards. 

To report a sighting of giant hogweed in Durham Region, please contact the Regional Weed Inspector with the location and description at the following email address: (Photo attachments of the plant are welcome)

  Further information on the plant may be obtained by calling the
  Invading Species Hotline at 1-800-563-7711.

For additional information on its control and to report sightings, please see one of the links below: