Proceedings of the Sixty-first Annual Meeting of the Northeastern ...

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GIANT HOGWEED ERADICATION IN PENNSYLVANIA AND SURROUNDING
STATES. M.A. Bravo, Pennsylvania Department of Agriculture, Harrisburg.
ABSTRACT
Heracleum mantegazzianum introduction to Europe, from its native Caucasus
Mountains, dates back to 1817. By the late 1840's reports of wild populations of giant
hogweed were documented in the United Kingdom. Currently 21 European countries
have reported wild populations of giant hogweed. In the United States an increase in
reports of wild populations is also occurring. Giant hogweed was added to the federal
noxious weed list in 1983. Giant Hogweed is in its element here in the temperate region
of the Northeastern states. In the last decade, 16 states (WA, OR, MI, IA, IN, WI, OH,
PA, NY, NH, ME, VT, MA, CT, NJ, MD) have confirmed finding giant hogweed. PA first
discovered giant hogweed in 1985 in Erie County. A joint effort between PDA and
USDA in 1998 established the Giant Hogweed Eradication Program. Currently, PA has
less than 600 sites with viable hogweed populations in 12 counties. Federal support for
the project has been strong and as a result of the PA efforts, many other States are
actively searching for Giant Hogweed and conducting outreach programs. In the fall of
2005, the Program Review Committee for Giant Hogweed met in Pennsylvania and
outlined the following goals for 2006. Goals for Pennsylvania and other States in the
Region for 2006 were 1) eradicating persisting, but isolated populations in outlying
counties 2) developing a standardized database to assist in evaluating the successful
of the eradication programs 3) acquiring regional staffing and funding to implement
control measures in adjoining states 4) emphasizing the risk of infestations becoming
established in riparian areas and 5) encouraging local and regional research on the
ecology an biology of giant hogweed to assist the eradication program in understanding
the long term population dynamics of this invasive species. Like most invasive primers,
giant hogweed’s reproductive potential is enormous. Plants reproduce by seed and
perenniating crown and rootbuds and have a high regeneration ability to set seed if
seed heads are removed prior to maturity. A single plant is capable of yielding more
than 100,000 seeds, primarily by out-crossing. Rosettes of giant hogweed can persist
for as long as 12 years before flowering and understanding the biology of giant
hogweed is critical to implementing a successful eradication program.
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