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:

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!

How do you identify giant hogweed?

Giant hogweed is a biennial or perennial herb in the carrot family (Apiaceae) which can grow to 12 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. If you need additional information or assistance in identifying your plant, you may call NYS Dept. of Environmental Conservation at 845-256-3111. You will be asked to describe the plant height, stem color, leaf shape, flower color and shape, as well as give directions to the plant site. If you can, take digital photos and email them to NYS Dept. of Environmental Conservation, to help identify the plant.

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 York, Pennsylvania, Ohio, Maryland, Oregon, Washington, Michigan, Virginia, Vermont, New Hampshire and Maine. Seeds may also be distributed by birds and waterways, and can remain viable for over 10 years. There are current confirmed locations of giant hogweed sites in New York State. Check the DEC site for details.