Giant Hogweed - Destroy Nuisance Weeds
What is it?
- An invasive plant.
- The sap of Giant Hogweed can negatively affect human health.
- Can be found along roadsides, vacant lots and stream banks.
Giant Hogweed Sap Can Cause:
- Serious skin inflammation (photodermatitis).
- The skin to be highly sensitive to UV rays due to a chemical called furanocoumarins.
- Skin blisters, redness, scarring, and other discolouration that can last for years.
- Temporary or permanent blindness if sap enters the eyes.
- Reactions that can occur for up to 48 hours after contact.
- Heat and moisture (sweat) can enhance the reaction.
What does it look like?
- 1 to 4 metres (3 – 14 feet)
- Large white clusters of small flowers
- Umbrella shaped
- 30 to 60 cm in diameter (1 to 2 feet)
- Up to 1 metre (3 feet) in diameter
- Sharp coarse teeth
- Compound leaves deeply divided into lobed toothed leaflets
- Produces watery sap
- Rough and bumpy
- Course white hairs emerging from bumps
- Purple/red splotches
How can I be exposed to the sap of giant hogweed?
- Touching or brushing up against the plant.
- Touching clothing or pets that have come into contact with the plant.
- The sap can become airborne by pulling, cutting or mowing giant hogweed. This can cause sap to get in the eyes.
What do I do if I accidentally come into contact with giant hogweed?
- Wash the affected area immediately with soap and water.
- Keep the affected area out of the sun for at least 48 hours.
- Seek medical attention.
What we do?
- Inspect locations
- Control and treat hogweed with pesticides as permitted by Community Standards By-law 2008-0138
If you find giant hogweed on municipal property please contact Public Works at
905-873-2601 Ext. 2603.
If you suspect Giant Hogweed is on your property:
- DO NOT TOUCH!
- Keep children and pets away from the area.
- You are encouraged to contact a licensed weed exterminator. They can be found under “Weed Control Services” in the Yellow Pages.
- If you choose to remove giant hogweed yourself, USE EXTREME CARE.
- Information on Giant Hogweed removal methods and how to report a sighting can be found at www.ontarioinvasiveplants.ca
DO NOT compost the plants.
- DO NOT place out for curbside collection either as Leaf & Yard Waste, Green Cart or waste material.
- Giant hogweed must be taken to the Halton Waste Management Site for safe disposal.
- Monitor the area for future growth.
- Community Standards By-law 2008-0138 Part 3, Section 8 Nuisance Weeds states "Property Owners are required to destroy and remove all nuisance weeds and weed seeds on their land." Also see amendment: By-law No. 2014-0031.
For more information on the Giant Hogweed please follow these links: