Virginia Tech researchers who helped identify the dangerous Giant Hogweed plants in Clarke County, Virginia, want residents to stay on the lookout for the plant with toxic sap that can cause severe burns — but also stressed that the weeds are believed to have been planted intentionally decades ago and haven’t spread in the years since.

“It’s a dangerous plant but I’m not overly concerned about it. This seems to be an isolated incident,” said Virginia Tech’s Michael Flessner, an assistant professor and extension weed science specialist.

Giant Hogweed is a Tier 1 Noxious Weed in Virginia and should be reported to the Virginia Department of Agriculture and Consumer Services. Prior to last week it had not been confirmed in the state. Flessner worked with Jordan Metzgar, curator of the Massey Herbarium at Virginia Tech, and Virginia Cooperative Extension Agent Mark Sutphin to identify the plant last week.

Property owners who think they spot Giant Hogweed should not panic, Metzgar said. He stressed that Giant Hogweed, with its white, umbrella-shaped-flower clusters, looks very similar in appearance to cow parsnip, a plant that’s widespread and native to Virginia. Giant Hogweed can grow to be up to 14 feet tall while cow parsnip is generally shorter.

Cow parsnip can also cause a mild skin rash but isn’t nearly as dangerous as Giant Hogweed.

Anyone who suspects they have found Giant Hogweed should take photos, check online to compare the plant to photos, and then contact a Virginia Cooperative Extension agent or the Virginia Department of Agriculture and Consumer Services.

No one should mow or use a weed trimmer to remove either Giant Hogweed or cow parsnip without wearing proper covering and safety gear, Flessner said.

Giant Hogweed is found in a number of other states, primarily to the north of Virginia.

Giant Hogweed
A Virginia Cooperative Extension Agent helped to identify 30 plants of Giant Hogweed in Clarke County, near Winchester.

Giant Hogweed can grow to 14 feet tall.

hogweed