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Giant Hogweed

Do Not Touch This Plant!



Giant hogweed can grow to 14 feet or more 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.

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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 Full giant hogweed plant



Giant hogweed stem Giant hogweed stem



Giant hogweed leaf Giant hogweed leaf



Giant hogweed flower Giant hogweed flower



Giant hogweed seeds 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.

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.



Giant Hogweed Poster 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.

The following helpful links leave the DEC website:





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