Giant Hogweed
Do Not Touch This Plant!
Giant hogweed can grow to 14 feet or more
Giant hogweed (Heracleum mantegazzianum) is a VERY LARGE, invasive plant that can cause painful burns and permanent scarring. Brushing against or breaking the plant releases sap that, combined with sunlight and moisture, can cause a severe burn within 24 to 48 hours. Giant hogweed is a Federally listed noxious weed and NYS law prohibits its possession with the intent to sell, import, purchase, transport, introduce or propagate.
On this page:
- What to do if you come into contact with giant hogweed
- Identification
- How to report giant hogweed
- DEC's Giant Hogweed Control Program
- New Yok State giant hogweed locations
- Giant hogweed outreach materials
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 to 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. Examples below:
Full giant hogweed plant
Giant hogweed stem
Giant hogweed leaf
Giant hogweed flower
Giant hogweed seeds
Report: Email DEC or call the Giant Hogweed Information Line: 845-256-3111. Provide photos, detailed directions to the plant infestation (GPS coordinates and street address a plus) and estimate the number of plants.
NYSDEC Giant Hogweed Control Program
From late April through August, DEC field crews visit each confirmed giant hogweed site, and use the appropriate control method. This is free of charge to the landowner. In general, root-cutting is used at smaller sites with less than 400 plants, herbicide is used at larger sites with greater than 400 plants and flower/seed head removal is used at all sites to limit seed dispersal. Sites are visited each year until the plants are eradicated. When no more plants are found the site will be monitored for three subsequent years.
For a site to be visited and controlled, landowners must give annual permission. For crews to use herbicide control, landowners must first sign a property permission form.
Past years' annual reports:
- 2021 Giant Hogweed Program Annual Report (PDF, 15MB)
- 2020 Giant Hogweed Program Annual Report (PDF)
- 2019 Giant Hogweed Program Annual Report (PDF)
Where Giant Hogweed is 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.
Help Spread the Word About Giant Hogweed
Giant Hogweed Poster
Distribute giant hogweed brochures and hang the giant hogweed poster where people will see it (e.g. town hall, post office, schools and library). Email DEC or call the Giant Hogweed Information Line at 845-256-3111 to let us know how many brochures and posters you can use. Provide your mailing address so we can mail them to you.
- Giant Hogweed Poster 18" x 24" (PDF, 9 MB)
- Giant Hogweed Poster 12" x 16" (PDF)
- Giant Hogweed Brochure (PDF)
- Giant Hogweed Fact Sheet (leaves DEC website)
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.
- 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
