“Heracleum mantegazzianum”
THIS IS A NOXIOUS, NASTY PLANT, and should be approached with great care!!! All control methods should be done with extreme care and only while wearing protective clothing and eye protection.
( Pictures Below )
***** Fact Sheet below paraphrased from the NYS DEC website. *****
Giant hogweed is a perennial herb with tuberous root stalks. It survives from one growing season to another by forming perennating buds (surviving from season to season) and enduring a period of dormancy during the winter. Flowers form from late-spring through mid-summer. Numerous (up to 100,000), half inch long, winged, flattened oval seeds form in late-summer. These seeds, originally green, turn brown as they dry and can be spread by animals, surface runoff of rain, or on the wind, establishing new colonies. Seeds can remain viable in the soil for up to 10 years. The plant’s stems die in the fall and remain standing through the winter, topped with the huge, brown dead flower heads.
Giant hogweed’s thick hollow stems are generally one to three inches in diameter but can reach four inches. Stems are marked with dark purplish blotches and raised nodules. Leaf stalks are spotted, hollow, and covered with sturdy bristles (most prominent at the base of the stalk). Stems are also covered with hairs but not as prominently as the leaf stalks. Leaves are compound, lobed, and deeply incised; can reach up to 5 feet in width. Numerous white flowers form a flat-topped, umbrella-shaped head up to two and a half feet across. The plant may grow to 15 to 20 feet in height.
Giant hogweed is one of a handful of plants in the Northeast that can cause a significant reaction when humans come in direct contact with the plant. For giant hogweed to affect a person, sap from a broken stem or crushed leaf, root, flower or seed must come into contact with moist skin (perspiration will suffice) with the skin then being exposed to sunlight. Irritation is not immediate, but will usually appear within one to three days after exposure. This form of skin irritation (dermatitis) is called “phytophotodermatitis”. The plant’s clear, watery sap contains a glucoside that sensitize the skin to ultraviolet radiation and can result in severe burns, blistering, painful sores, and purplish or blackened scars. The worst risk of exposure to giant hogweed is to one's eyes - getting even minute amounts of the sap in the eyes can result in ttemporary or even permanent blindness. Medical help should be sought immediately; by the time symptoms of burning and hypersensitivity to sunlight are apparent, the damage could already be irreversible.
Giant hogweed is very difficult to eradicate. Cornell Cooperative Extension recommends early application (during the bud stage and the period of active plant growth) of glyphosate. For those hesitant to utilize herbicides, giant hogweed can be managed using various “cultural” methods. Unfortunately, owing to the plant’s persistence and spread by blowing seeds, such control can take many seasons worth of effort to achieve 100% control. Individual plants can be dug out, removing the entire rootstalk, a difficult process, particularly in patches where the plant has spread by root growth. Unfortunately, unless performed numerous times during a season, mowing only serves to stimulate budding on the rootstalk.
If you find giant hogweed in NYS, you are strongly encouraged to call the Giant Hogweed Hotline: 1-800-554-4501 Ext. 72087
….however if you want it eradicated, unfortunately they don’t have it in their budget, so you may call me, and I will set up a program to control it for you………
