Giant worries over hogweed


Its stalks stretch to 14 feet into the air, its blooms are bigger than a human head, and its sap can blind a man.

The invasive giant hogweed has been growing in Berkshire County for almost a decade, but that makes its presence no less alarming, according to Jennifer Orth, who works at the agency that tracks the weed.

"We have lots of invasive plants that cause ecological problems, but this is one of few that threatens human health as well," said Orth, of the Massachusetts Introduced Pests Outreach Project, a collaboration between the University of Massachusetts and the state Department of Agricultural Resources.

The department is monitoring and attempting to eradicate outbreaks of the poisonous plant at isolated sites in Hinsdale and New Marlborough. Across the state, the plant has been found in 17 cities and towns.

The plant, which grows along roadsides, in vacant lots and along streams, produces sap that can cause severe blisters on the skin. A New York Department of Environmental Conservation report compares the danger posed by hogweed to that of poison ivy. But, according to the release, even a small amount of sap in the eye can cause temporary and sometimes permanent blindness.

The Eagle was unable to confirm any reports of blindness or even blistering associated with the Berkshires outbreaks, but Jim Wilusz, director of the Lee-based Tri-Town Health Department, said any cases would have been treated by private physicians and wouldn't have been reported to local health boards.

According to the U.S. Department of Agriculture, there are severe outbreaks of giant hogweed in Pennsylvania, Connecticut and western New York, although there are documented stands of hogweed in neighboring Rensselaer County, N.Y.

The Massachusetts Introduced Pests Outreach Project has been tracking hogweed since 2003. Residents can report sightings to the state at, which also features a hogweed identification guide.

Orth said the plant's massive blooms -- made up of tiny, white flowers -- produce a tremendous number of seeds, which are dispersed by the wind.

She said the known outbreaks of giant hogweed in Berkshire County haven't been spreading because they are being monitored. The agency will consider them eradicated after it has been able to document that no new plants have sprouted for five consecutive years.

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Orth said the plant initially was introduced to the region by gardeners who apparently were taken by its pleasing appearance.

"It's a very striking plant, particularly when it flowers," she said.

It's illegal to sell giant hogweed in Massachusetts. Still, occasionally a plant slips through the cracks.

"Sometimes people don't realize that it's banned and poisonous, so they try to grow it," Orth said.

Hogweed facts

Grows to between 7 and 14 feet high.

Has umbrella-shaped flower clusters up to 21 2 feet across.

Has lobed leaves up to 5 feet across.

Has green stems with extensive purple splotches.

For a complete identification guide, and to report suspected outbreaks, go to


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