Giant Hogweed

B. Brown J. Hallworth Fraser Valley Regional District

Plant Bio

Common Name:Giant hogweed
Classification/Rank:Extremely Invasive
Method of Transportation:Seeds are transported by wind, water, animals and human activities. Plant produces 100 000 seeds that are viable for 15 years in the soil.
Habitat/Range:Rich, damp soil and various light conditions. Forms colonies along roadsides, ditches, in vacant lots and disturbed sites. Thrives along stream and river banks, in wetlands and in riparian zones.


Giant hogweed is a massive plant with the potential to become extremely hazardous. Growing up to 6 meters tall this plant towers over local vegetation with leaves and flowers that can reach over 1 m in width. The leaves are deeply incised and maple like in appearance. The flowers are small, white and form an umbrella-shaped head. Stems are hollow, and ridged with purple spots. For more identification tips check out the Invasive Species Council of Metro Vancouver's website

Health Hazard: Giant hogweed's stems and leaves contain a clear sap that causes hypersensitivity to sunlight. If the sap comes in contact with the skin and is exposed to sunlight it can cause welts and burns that scar the skin for several years afterwards. Giant hogweed can also cause temporary or permanent blindness if it comes within eye contact. Water resistant gloves and clothing along with safety goggles are strongly recommended when working with this plant.

NOTE:  Fortunately Giant Hogweed has not been confirmed north of the Sheridan Lake area east of 100 Mile House, as reported sightings in the NWIPC area to date have been Cow Parsnip (Heracleum maximum). Cow Parsnip grow up to 2 m (6 ft), while Giant Hogweed is usually between 2 to 6 m (6 to 18 ft). Giant Hogweed leaves are much more deeply lobed compared to Cow Parsnip leaves. Download the two-page ISCBC TIPS document here. To report a site or request more information contact the NWIPC or use the Report-A-Weed App.


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