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Giant Hogweed

Do Not Touch This Plant!

A man standing next to a giant hogweed which towers over him
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 in Contact With Giant Hogweed

  • Wash the affected area thoroughly with soap and COLD water as soon as possible
  • Keep exposed area covered or away from sunlight for 48 hours
  • If a reaction occurs, topical steroids applied early can reduce the severity of the reaction and ease discomfort
  • If a reaction has occurred, the area of skin may be sensitive to sunlight for a few years and you may want to apply sun block or keep the affected area covered from the sun when possible
  • See a physician if you have a reaction or any questions
  • If sap goes in eyes, rinse them with water, wear sunglasses or cover your eyes, and seek emergency medical care IMMEDIATELY to prevent potential blindness


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. Some other plants look very similar.


Giant Hogweed and Common Lookalikes
Plant Flower Leaf Stem
Giant Hogweed

7-14 feet tall
This plant can cause burns.
Do not touch.

White umbrella-shaped flower clusters
up to 2.5 feet wide. 50+ rays per cluster.
Flowers late June - mid July

Compound, lobed, deeply incised,
up to 5 feet wide

Green with purple splotches and coarse
white hairs - thick circle of hairs at base of
leaf stalk, 2-4 inches in diameter.
Cow Parsnip

5 to 8 feet tall
This plant may cause burns.

White flat-topped flower clusters no longer
than one foot wide. 15-30 rays per cluster.
Flowers late May - Late June

Compound, less incised than hogweed,
between 2 - 2.5 feet wide

Green and rigid with fine white hairs
1-2 inches in diameter.
full angelica plant next to human
4 to 9 feet tall
This plant may cause burns.
angelica flower
Softball-sized and shaped clusters,
greenish-white or white
Flowers mid May - mid June
angelica leaf
Compound leaves that may extend
up to 2 feet wide
angelica stem
Smooth, waxy purple, 1 to 2.5 inches
in diameter (no hairs or bristles)
Wild Parsnip
wild parsnip full plant next to human
Up to 5 feet tall
Native of Eurasia
This plant can cause burns.
Do not touch.
wild parsnip flower
Single flower stalk with flat-topped
umbel of yellow flower clusters
Flowers late May - early July
wild parsnip leaf
Compound, pinnate, 5 to 15 toothed
leaflets, variably lobed, yellowish-green
wild parsnip stem
Yellowish-green with full length
grooves (no hairs or bristles)
Queen Anne's Lace
queen anne's lace plant
1 to 3 feet tall
Native of Eurasia
queen annes lace flower
Flat-topped umbel of white flower clusters,
2 to 4 inches wide. The central flower
cluster usually deep purple.
When fruiting, the umbel becomes
concave and resembles a "bird's nest."
queen annes lace leaf
Compound, pinnate, fern-like.
queen annes lace stem
Green, covered with bristly hairs.
Poison Hemlock
Poison hemlock stalk - 4 to 9 feet tall
4 to 9 feet tall
Native of Eurasia
All parts of this plant are very poisonous.
Poison hemlock flowers - small and white arranged in numerous flat-topped clusters on all branches
Small and white arranged in numerous
flat-topped clusters on all branches
Flowers late May - late June
Poison hemlock leaf - bright green, small and fern-like, may appear glossy
Bright green, small and fern-like,
may appear glossy
Poison hemlock stem - smooth and waxy stem with purple blotches, 1 to 2 inches in diameter
Smooth and waxy stem with purple
blotches, 1 to 2 inches in diameter
(no hairs or bristles)
Common Elderberry
a man looks at elderberry flowers on the shrub in front of a white house
Shrubs 5 to 12 feet tall
Spreads and forms thickets
white flowers with a hand and compass next to them for scale
White flat-topped or slightly rounded flower
clusters at branch ends, 2 to 6 inches
wide. Fruit is purple to black in color.
Flowers June - July
leaves on asphalt
Compound, pinnate, 5 to 11 toothed leaflets
a woody stem with a green stem growing out of it
Older woody stems or young green stems
with prominent lenticels (pores), no hairs
or bristles
a full pokeweed plant
Up to 10 feet tall
All parts of the plant are poisonous.
small white flowers popping out of a green stem
Greenish-white racemes (linear flower
clusters), with dark purple berries.
Flowers late June - October
a green stem with large green flowers on it
Alternate, large, entire leaves (not leaflets)

Green to red or purplish, smooth
stout stems, no hairs or bristles

Distribution and Habitat

Giant hogweed is a native of the Caucasus Mountain region between the Black and Caspian Seas. It was introduced 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, as well as in fields, forests, yards, and near roadsides. It grows in sunny areas and in partial shade, preferring moist soils.


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 management is decided by the size and number of plants:

  • 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:

What You Can Do To Help

Report Giant Hogweed

If you see giant hogweed, take a picture and 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 preferred) and estimate the number of plants.

thumbnail of giant hogweed awareness poster
Giant Hogweed Poster

DEC has giant hogweed publications for distribution. 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.

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  • Contact for this Page
  • Division of Lands & Forests
    Giant Hogweed Program
    21 South Putt Corners Road
    New Paltz, NY 12561
    Send us an email
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