Giant hogweed plant: don't touch
NEW YORK STATE--It's summer time and many plants are in full bloom--including some very harmful plants.
Giant hogweed (Heracleum mantegazzianum) is a federally listed noxious weed. Its sap, in combination with moisture and sunlight, can cause severe skin and eye irritation, painful blistering, permanent scarring and blindness. Contact between the skin and the sap of this plant occurs either through brushing against the bristles on the stem or breaking the stem or leaves. Giant hogweed is a biennial or perennial herb in the carrot family (Apiaceae) which can grow to 14 feet or more. Its hollow, ridged stems grow two to four inches in diameter and have dark reddish-purple blotches. Its large compound leaves can grow up to five feet wide. Its white flower heads can grow up to two and a half feet in diameter.
Giant hogweed grows along streams and rivers and in fields, forests, yards and roadsides. It prefers open sites with abundant light and moist soil but it can grow in partially shaded habitats, too.
If you encounter a hogweed plant, here are the directions from the state's Department of Environmental Conservation. Immediately wash the affected area thoroughly with soap and water and keep the area away from sunlight for 48 hours. This plant poses a serious health threat; see your physician if you think you have been burned by giant hogweed. If you think you have giant hogweed on your property, do not touch it. Notify the DEC of plant locations.
What are the symptoms of exposure to giant hogweed sap?
• Painful blisters that form within 48 hours and become dark and pigmented
• Scars that last up to six years, though typically only last a few months
• Long-term sensitivity to sunlight is common
• Blindness may occur if the sap gets into the eye
Where is the toxic sap located?
• Sap can be located in all parts of the plant but the following have higher concentrations: the lower part of the hollow stems and petioles; the hollow hairs on the plant; the foliage, stem, flower, or fruit (seed).
Safety precautions to follow when controlling giant hogweed plants:
• Do not touch the plant with bare skin
• Do not touch your bare skin with sap covered gloves
• Prevent UV sunlight from reaching skin by:
• wearing long waterproof gloves, long sleeves, pants, boots and eye protection; synthetic water-resistant materials are best since cotton and linen fibers can soak up the plant sap and be penetrated by plant hairs
• If controlling plants with multiple people, keep a good distance from one another as the sap can splash three to four feet
• Apply sun block before beginning to work
• Launder clothes that may have contacted plants
• Wash equipment with water immediately after use
• Limit exposure to sunlight after control or work around giant hogweed plants after sunset
• Do not use a "weed-whacker" or brush cutter--sap may splatter as stems are cut
• Keep water, soap, and eye-wash near work area in case of exposure
What should you do if you are exposed to giant hogweed sap?
• Wash the affected area thoroughly with soap and cold water as soon as possible
• Keep exposed area away from sunlight for 48 hours
• If a reaction occurs, topical steroids applied early can reduce the severity of the reaction and ease discomfort
• If sap goes in eyes, rinse them with water and wear sunglasses
• If a reaction has occurred, the area of skin may be sensitive to sunlight for a few years and you may want to apply sun block or keep the affected area covered from the sun when possible
• See a physician if you have a reaction or any questions.