What You Need To Know About Giant Hogweed, A Dangerous Plant That Causes Severe Burns


Summertime means fun in the sun — and avoiding poison oak at all costs. While poison oak symptoms are annoying, they seem like a walk in the park compared to a dangerous plant that has been spotted across the United States.

Heracleum mantagazzianum — better known as giant hogweed — is an invasive plant that oozes a toxic sap. The clear, watery sap can cause third-degree burns and serious blisters on skin that is exposed to sunlight (called phytodermatitis). And if the sap were to get into your eyes, it could also cause permanent blindness.

More than just a pretty plant, the giant hogweed is a serious public health concern.

Where Giant Hogweed is Found

Considered a noxious weed by the U.S. government, giant hogweed has large umbrella-shaped white flower clusters, similar to those of Queen Anne’s lace. It grows along streams and rivers, as well as in fields, forests, yards, and roadsides, and can reach up to 14 feet tall.

Although the plant is native to the Central Asia region, giant hogweed has been found in Virginia, Connecticut, North Carolina, Maine, Massachusetts, Vermont, New York, Pennsylvania, Michigan, Illinois, Washington, and Oregon.

The invasive weed has also been spotted recently in Guelph, a city in southwestern Ontario, Canada. Officials took to the City of Guelph’s Twitter account to warn residents about giant hogweed and how to report the plant on city property. Fortunately, it was removed before dropping any seeds.

How to Keep Yourself Safe
There are several different ways to get rid of the most common weeds, some of which include using natural materials like salt or vinegar. But giant hogweed requires special handling and is better left to professionals. You should never, ever use a weedwhacker on giant hogweed because it can spread the dangerous sap, as well as seeds, around. Both the plant and its roots should be removed.

Above all else, avoid giant hogweed if you see it. The New York State Department of Environmental Conservation took to Twitter to issue a warning to residents not to touch it:

How to Treat Symptoms
If you believe you’ve spotted giant hogweed, report the sighting to your local authorities immediately. But if you or a loved one happens to come into contact with the plant, wash that part of your skin right away with soap and water, then visit your doctor as soon as possible for further treatment. If you are not near soap and water (i.e. you are out of doors), you can put sunscreen on the affected area to prevent the reaction from exacerbating.


Washing your skin should minimize the symptoms, which take about 15 minutes to show up. You should also cover up the affected area for at least 48 hours. If the sap gets into your eyes, flush them right away with water and wear sunglasses — i.e., keep the affected area out of sunlight — for at least two days.

Giant hogweed is a dangerous weed, so staying vigilant is important. Be careful out there!