If You See Hogweed, Report It
Cottage Country Tips & Advice, Professional Entertainers

Don’t touch Giant Hogweed!

Make sure you are careful on the roadsides and in the parks this summer.

Most people know about poison ivy, but there is a new, much more poisonous plant invading Ontario’s outdoors and putting workers at risk. It’s called giant hogweed.


Who is at risk? … Outdoor workers in southern Ontario can encounter giant hogweed near roadsides, streams, vacant lots, and waste areas.

What does it look like?

If You See Hogweed, Report It
Don’t Touch. If You See Hogweed, Report It

Giant hogweed is a tall plant that grows up to an astonishing five metres high. Small whisker-like hairs and reddish-purple spots cover its stem. From June to August, it produces a white flower that resembles an umbrella and can stretch one metre wide. Various parts of the plant (including stems and leaves) release a clear watery sap that is extremely toxic.

How can it hurt you?

Giant hogweed is very poisonous: • Skin contact with the sap in the presence of UV light (such as sunlight) can cause swelling, itching, and blistering that lasts for months. Some people then become sensitive to UV light and experience a skin-color change that can last for years. • If the sap gets into your eyes, it can cause permanent blindness. How can we control the hazard? • Never touch or brush up against the plant with bare skin. • If you must work near the plant, cover all body parts using impermeable coveralls, gloves, and a face shield to protect the eyes and face. • Avoid using power tools near the plant because breaking or crushing the stem or leaves can release the toxic sap.

What do I do if you are exposed?

Wash the affected area immediately with soap and water. • Stay out of sunlight and cover up exposed areas. • Get medical attention immediately.

For more information, contact IHSA or Ontario’s Ministry of Agriculture, Food and Rural Affairs at 1-877-424-1300.