Certain native and invasive species produce a photo-toxic sap containing furanocoumarins within their stems and leaves. This chemical makes the skin more vulnerable to ultraviolet light, causing hyper sunlight sensitivity (phytophotodermatitus), severe burns and blistering, skin discoloration, and in some cases it can cause blindness if it gets into the eye. Others can be highly toxic if ingested by humans or animals. If you ingest any toxic plants, seek immediate medical help.
If you are working around these photo-toxic plants, wear gloves, long-sleeved shirts, pants, boots, and eye protection to avoid coming into contact with the sap. If you do come into contact with their sap, immediately wash with soap and water. This will minimize the effects of the solution but will not fully prevent some of the symptoms. If strong symptoms arise, seek medical treatment. Untreated, the rash/burns could persist for up to 2 weeks, while the sunlight sensitivity could persist for up to 2 years. Keeping exposed skin covered will help with preventing severe burns.
Manual removal of these plants can be effective in small areas. The DEC recommends that pulling of these plants be done before they have gone to seed. If removal occurs after they have gone to seed, cut off the seed heads, place them in plastic bags, and leave them out in the sun for one week to kill the seed heads. Once the seed head is no longer viable, it can now be disposed of. Mowing of these plants after they have bloomed, but before they come to seed can also kill the plants. In some cases it may require a second go, as they can re-sprout. Herbicides can also be applied as spot treatments to new growth. Please refer to How to Control Giant Hogweed for more information on how to safely remove Giant Hogweed and other equally harmful plants from your property.
Giant Hogweed (Heracleum mantegazzianum) is native to Asia, but invasive to North America. It can reach heights of 14 feet or more with thick, hollow stems with ridges and purple blotches. The large compound leaves can reach up to 5 feet wide while it’s white flower heads can reach 2 ½ feet in diameter.
DO NOT TOUCH THIS PLANT
If you believe you have identified this plant on your property, please take several photos of the plant including the leaves, stem, flowers, and seeds (keeping a safe distance of course) and contact DEC or call the Giant Hogweed Hotline: 1-845-256-3111.