Agricultural Spotlight on Heracleum mantegazzianum
Hi everyone. Over the past few weeks, a plant called Giant Hogweed has been in the news and I am sure you have been wondering if we have any around here. Hogweed is a biennial member of the carrot family, a large member! It really can grow to 12 feet but most often it is only 6 to 8 feet in height when it flowers. The flower looks very much like Queen Anne’s lace only it is the size of a hula hoop. The sap can cause severe burns if the juice is not washed off and your skin is exposed to sunlight for an extended period of time. The sap is also concentrated in the seeds and in the roots. The burn is called a phyto-photo-dermatitis reaction and it can result in a severe 2nd and even a 3rd degree burn in extreme cases. Unfortunately, it is also highly invasive once it hits the riparian corridor and moves out into the flood plain during flooding instances. Because it is a federal noxious weed it is illegal to plant, sell or trade this plant. Mostly what we see now are wild populations that keep spreading. Many homeowners still have this plant in their landscape beds and are unaware the plant is regulated and do not know about the plant’s poisonous sap until the accidentally get burned by it.
I was the Giant Hogweed Program Manager for Pennsylvania from 2005 to 2012. I recently conducted a radio interview on the plant and its poisonous attributions. We have linked to the radio podcast on our Agricultural Spotlight feature today.
PA Program: Pennsylvania discovered its first wild population of giant hogweed in 1985 in Erie County two years after the federal government declared the plant a noxious weed. GH has probably been in Pennsylvania since the early 1900’s but only in the last 25 years have wild populations been reported to officials. Rochester, NY has records of plant sightings dating to the early 1900’s.
In 1983, the United States Department of Agriculture Plant Pest Health Inspection Service (USDA-APHIS) declared the plant a federal noxious weed and targeted giant hogweed (GH) for eradication nationwide. As of 2011, GH had been found in 18 states and in Canada. It was added to the PA Noxious Weed Control List in 2000. The Pennsylvania Department of Agriculture (PDA) and USDA/APHIS launched the GH Hotline in 1998 and created a national giant hogweed campaign to promote awareness of this poisonous plant.
As of 2012, the last year I worked on the program, 453 sites have been found in 17 PA counties. My crew and I worked throughout the state educating homeowners and eradicating the infestations with mechanical and chemical control measures. The closest population to Tioga County was in Potter County along the streambank below Carter Camp to Ole’ Bull Park and a few sites in Port Allegany. More than 55% of the Pennsylvania populations were found in Erie County. Nearby sites are known in Crawford, Mercer, McKean, Venango, and Warren Counties. Isolated sites are also known from Elk, Potter, Butler, Blair, Huntingdon, Carbon, and Wayne counties.
The state wide targeted eradication program was very successful and we declared 325 of these sites eradicated in 2012. As of 2012, only 74 (16%) of the 453 known sites in Pennsylvania remained active. However stream bank sites must always be monitored as seed may be reintroduced during flooding events.
While I was with the program my staff assisted Ohio, NJ, MD and New York with training and control of identified populations. NY soon discovered they had even more infestations than PA and began a state wide eradication program in 2011. Thanks to media coverage, they quickly identified more than 900 sites in 35 counties in the first year. The program is ongoing and they are doing a great job on outreach and assisting landowners. Here is the link to the NY program.
If you have any questions or concerns about poisonous plants on your property please give me a call at 814-574-4067.
Photos provided by Melissa Bravo