Wednesday, June 19, 2024

How to identify giant hogweed, a harmful invasive species

Field technician cutting off flower heads to prevent the spread of giant hogweed.

Giant hogweed plants are beginning to bloom across many parts of the state, making it a prime time to spot this harmful invasive species. Giant hogweed is a large, flowering plant from Eurasia with sap that can cause painful burns and scarring.

Adult giant hogweed plants tend to be 7-14 feet tall with an umbrella-shaped cluster of white flowers up to 2.5 feet wide. The stem is green with purple splotches and coarse white hairs, and leaves are large (up to 5 feet across), incised, and deeply lobed. The most common lookalike found in NY is our native cow parsnip, which flowers earlier and does not have the purple splotches on the stem (but can also cause burns). You can find more identification tips, including a table of other lookalikes, on our website.

If you think you have found giant hogweed:

  • Do not touch it.
  • From a safe distance, take photos of the plant’s stem, leaves, flower, seeds, and the whole plant.
  • Report your sighting to DEC by emailing photos and location information to or by calling (845) 256-3111. DEC staff will help you identify whether the plant is giant hogweed and provide you with information about giant hogweed control methods and DEC’s control program.
  • If the plant is confirmed to be giant hogweed, DEC will seek permission from the landowner for a field crew to visit and perform giant hogweed control at no cost.

Photo at top: Field technician cutting off flower heads to prevent the spread of giant hogweed. NYS DEC photo.

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Information attributed to NYSDEC is taken from press releases and news announcements from New York State's Department of Environmental Conservation.

One Response

  1. Boreas says:

    I wish articles warning of the toxicity of this plant included pictures in ALL stages of growth. GH doesn’t just “show up” as 9 foot plants, but obviously GROWS to that stage. I assume it is toxic at all stages. I do a lot of weeding, but I wouldn’t attack anything 9 feet tall. But it seems to look a lot like Queen Anne’s lace or wild carrot and It would be nice to see more pictures of the young plants. Even the DEC website didn’t help much in that regard.

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