An invasive weed that can cause severe burns, blisters, scars, and blindness is spreading — here’s what you should know about giant hogweed
- Giant hogweed, an invasive plant, was recently discovered in Virginia for the first time.
- Giant hogweed sap can make skin extremely sensitive to the sun, leading to third-degree burns in a short period. It can cause blindness if it gets in an eye.
- If you encounter the plant, don’t touch it. And if you may have been exposed to the sap, stay out of the sun and see a doctor if you experience a reaction.
The giant hogweed plant is originally from the Caucasus region, between the Black Sea and the Caspian Sea where Europe and Asia meet. In the early 20th century, the herb was introduced to the US as an ornamental garden plant, as its impressive white flower heads can reach 2 1/2 feet in diameter.
This was a bad idea.
The plant’s sap, which people can encounter when they break the stem or leaves or brush against its bristles, can make skin extremely sensitive to the sun, leading to third-degree burns in a short period. Scars from the burns can last for years, and the reaction can cause blindness if sap gets in a person’s eye.
Giant hogweed, now federally classified as a noxious weed, has been found in Virginia for the first time, the Massey Herbarium at Virginia Tech announced last week. At least 30 plants were found at a site in Clarke County.
These plants had previously been found growing in other states in the Mid-Atlantic and New England – including in New York, Pennsylvania, and Massachusetts – and in the Pacific Northwest in Oregon and Washington. The US Department of Agriculture’s website shows it has also been found in Michigan and Illinois.
- NY DEC/Flickr
What giant hogweed looks like
Giant hogweed (Heracleum mantegazzianum) is technically a biennial or perennial herb in the carrot family.
- NY DEC
According to the New York Department of Environmental Conservation‘s identification guide, the plant tends to be 7 to 14 feet tall, with clusters of 50 to 150 flowers that spread as far as 2 1/2 feet across.
Massive leaves can stretch 5 feet across.
Green stems are splotched with purple and have coarse white hairs, which carry the plant’s dangerous sap.
Giant hogweed also produces thousands of dry, flat, oval seeds, which are about three-eighths of an inch long and have brown lines.
Several plants are often confused with giant hogweed, including cow parsnip, angelica, Queen Anne’s lace, wild parsnip, and poison hemlock.
- NY DEC
While giant hogweed was often planted for ornamental reasons, it can spread if soil containing the plant or its seeds are moved, or if the wind or a person or animal carries seeds to a new location.
What to do if you find giant hogweed
If you happen to find giant hogweed out in the wild, don’t take a weed wacker to it, as it can dangerously spray the sap around.
There are specific procedures to ensure the plants are killed and certain herbicides legal for use by a licensed pesticide applicator.
If you or someone you know brushes against one of these plants, experts recommend immediately washing the affected area with soap and cold water and keeping it out of the sun for at least 48 hours. (The reaction can begin within 15 minutes of exposure.)
If you think you’ve been burned by a reaction after coming into contact with giant hogweed, see a physician immediately. Topical steroids can reduce the severity of the burns.
If sap gets into your eyes, rinse them and wear sunglasses.
After a burn, skin can be especially sensitive to sun exposure for several years.
In general, the Department of Environmental Conservation recommends contacting it (or the corresponding department in your state) for professional removal.