Giant Hogweed

Giant Hogweed

Giant Hogweed plantGiant Hogweed (Heracleum mantegazzianum) is an invasive plant species that can cause health issues in humans, and is dangerous to the plant ecosystem. It is native to the Caucasus region of Eurasia and was likely introduced to North America as an ornamental garden plant. It is usually found along road beds, streambeds and forest edges. Hogweed can reach a height of approximately 4.5 metres (15 feet). It has hollow stems with dark reddish-purple splotches and coarse white hair. The leaves can grow up to 1.5 metres (5 feet) wide and have hairs on the underside. The plant also produces flattened oval shaped fruit and white flowers. Giant Hogweed resembles cow parsnip, Queen Anne’s Lace (wild carrot) and Angelica, but is much larger.

Giant Hogweed has a clear watery sap on the stems and leaves that burns the skin when exposed to sunlight. The initial burning red rash progresses to form blisters, resembling a burn. If you come in contact with Giant Hogweed:

  • Avoid touching your eyes or wiping the sap on other parts of your body or clothes.
  • Wash affected areas immediately.
  • Keep the affected area out of the sun.
  • Seek medical advice.
  • If it is possible that your pet has had contact with the sap from Giant Hogweed, it is important not to touch your pet with bare hands. The sap will likely not affect your pet, but there is potential that you could get the sap transferred to your skin via your pet's fur. Using protective gloves, immediately wash your pet with soap and water and seek medical attention if you feel you have been exposed. Seek the advice of a veterinarian if you have concerns about your pet.

If you suspect you have found Giant Hogweed in a park, playground or open space do not touch the plant and contact the City by calling Access St. John's at 311 or (709) 754-CITY (2489).

If you find Giant Hogweed on your own property, it is strongly recommended that you contact a landscape professional to identify and remove the plants. The City does not remove plants from private property.

For additional help, contact information or to submit a request visit Access 311.