Environmental Health: Giant Hogweed

What is Giant Hogweed?

• Giant Hogweed is an invasive plant that looks similar to cow parsnip.
• The plant can reach a height of approximately 15 to 20 feet.
• The plant has hollow stems with dark reddish-purple splotches and coarse white hair.
• The leaves of the plant can grow up to five feet in width and have hairs on the underside.
• The plant also produces flattened oval shaped fruit and in the summer, small white flowers form.

Photos courtesy of
http://www.coquitlam.ca/Residents/Public+Safety/
Health+Safety/Giant+Hogweed.htm

Where has the plant been found?

• Giant Hogweed has been found in all three area municipalities in Peel.

Is Giant Hogweed a risk to human health?

• Yes.
• A clear and watery sap is found in the stem and hairs of Giant Hogweed. Contact with the sap can cause a skin reaction whereby skin becomes sensitive to the ultraviolet light in sun light.
• Reactions can occur up to 48 hours after contact, and sensitivity can lead to painful blisters and burns.
• Blisters can lead to pigmented purple and black scars that may last for long periods.
• In addition, contact with the eyes can cause temporary and sometimes permanent blindness.

Burn caused by giant hogweed

Photo: USDA APHIS PPQ Archive, USDA APHIS PPQ, www.Bugwood.org, www.forestryimages.org.
This photo is licensed under a Creative Commons Attribution 3.0 United States License.

What should I do if I come in contact with Giant Hogweed?

• Wash affected areas immediately
• Keep the affected area out of the sun
• Seek medical advice

What do I do if I find Giant Hogweed in my backyard?

1. If you suspect you have Giant Hogweed growing on your property, the Region of Peel recommends that you hire a lawn care professional to remove the plants.
2. If you wish to remove the Giant Hogweed on your own, please adhere to the following procedures for your safety:

• Wear protective clothing, including gloves, long sleeves, pants, and eye protection, rain coat and boots
• Avoid getting sap on your skin
• Immediately remove any flower heads to prevent seed growth and dispersal
• Sever the plant roots 8 – 12 cm below the soil surface
• Dispose of all plant parts in double-bagged garbage bags. Seal the bags and label them with the words “Giant Hogweed.” Call the Region of Peel at 905-791-9499 (or 905-584-2216 in long-distance areas) to arrange for special pick-up, free of charge.
• DO NOT compost or put in your yard waste or green bin containers. Giant Hogweed will not be collected at the curb.
• Return to plant site periodically to remove any new plant growth
• Wash the clothes you wore to remove the plant afterwards

Who should I call if I find Giant Hogweed in a park or other area?

Call Parks Department at your local area municipality.

• City of Brampton, Parks and Recreation 905-874-2300
• City of Mississauga, Recreation and Parks 905-615-4100
• Town of Caledon, Parks and Trails 905-584-2272