Do Not Touch This Plant!
Giant hogweed can grow to 14 feet or more
Giant hogweed (Heracleum mantegazzianum) is a Federally listed noxious weed. Its sap, in combination with moisture and sunlight, can cause severe skin and eye irritation, painful blistering, permanent scarring and blindness. Contact between the skin and the sap of this plant occurs either through brushing against the bristles on the stem or breaking the stem or leaves.
What to do if you come in contact with giant hogweed:
Immediately wash the affected area thoroughly with soap and water and keep the area away from sunlight for 48 hours. This plant poses a serious health threat; see your physician if you think you have been burned by giant hogweed. If you think you have giant hogweed on your property, do NOT touch it. Please refer to our Health Hazards & Safety Instructions for Giant Hogweed for more information.
How do you identify giant hogweed?
Giant hogweed is a biennial or perennial herb in the carrot family (Apiaceae) which can grow to 14 feet or more. Its hollow, ridged stems grow 2-4 inches in diameter and have dark reddish-purple blotches. Its large compound leaves can grow up to 5 feet wide. Its white flower heads can grow up to 2 1/2 feet in diameter. Please refer to the Giant Hogweed Identification page for further help. Some other plants look very similar.
What to do if you see giant hogweed:
Identify: Use the key on our giant hogweed identification page to try and make a positive identification. Other plants that look similar are also shown.
Photograph: Photos are needed to confirm identification. Take high resolution photos of the entire plant, stem, leaves, flowers and seeds, making sure to keep a safe distance.
Report: Email DEC or call the Giant Hogweed Hotline: 1-845-256-3111. Provide photos, detailed directions to the plant infestation and estimate the number of plants.
Control: If giant hogweed is confirmed, DEC will contact the landowner and may visit to assess the site and discuss management options, as resources allow.
Where is giant hogweed found?
Giant hogweed is a native of the Caucasus Mountain region between the Black and Caspian Seas. It was introduced to Europe and the United Kingdom in the late nineteenth century and to the United States in the early twentieth century as an ornamental garden plant. It has become established in New England, the Mid-Atlantic Region and the Northwest. Giant hogweed grows along streams and rivers and in fields, forests, yards and roadsides. It prefers open sites with abundant light and moist soil but it can grow in partially shaded habitats, too. The map to the right displays the current confirmed locations of giant hogweed sites in New York State.
Help spread the word about giant hogweed:
Print the giant hogweed poster and hang it where people will see it (e.g. town hall, post office, schools and library). This poster will help people learn how to identify giant hogweed, know to avoid touching it, and encourage them to report giant hogweed locations to NYSDEC so we can help control it. The print size of this poster is 18x24 and 12x16 inches but it can also be printed smaller by adjusting your printer settings.
- Giant Hogweed Poster 18" x 24" (PDF, 9 MB)
- Giant Hogweed Poster 12" x 16" (PDF, 350 KB)
- Giant Hogweed Brochure (PDF, 660 KB)
- Conservationist Article (PDF, 360 KB)
- Cornell Pest Alert (PDF, 255 KB)
- Giant Hogweed Fact Sheet (PDF, 890 KB)
The following helpful links leave the DEC website.
- Invasive Plants of the Eastern US
- NYS Department of Health
- Cooperative Agricultural Pest Survey (CAPS)
- NY iMap Invasives
More about Giant Hogweed:
- Giant Hogweed Identification - This page has photos of all parts of the giant hogweed plant as well as photos of common lookalike plants for identification purposes.
- Health Hazards & Safety Instructions for Giant Hogweed (with graphic photos) - This page describes the health hazards of giant hogweed and details how people should protect themselves against the harmful sap.
- How To Control Giant Hogweed - A variety of methods for controlling this non-native invasive plant.
- NYSDEC Giant Hogweed Control Program - Details the statewide giant hogweed control program protocol.
- Giant Hogweed Statewide Distribution Map - Statewide distribution and density of giant hogweed sites by county.
- Giant Hogweed Eliminated Sites Map - Sites that previously had giant hogweed. These sites were treated and no longer have giant hogweed.
- Giant Hogweed Biology - This page describes the biology of giant hogweed plants to include their growth and devlopment stages, seed dispersal and viability, as well as the habitat and competition for giant hogweed plants