Monday, June 6, 2011

Hogweed Losing in PA

It has a flower that is as big as a hula-hoop and it is related to the carrot, so why is the state trying to get rid of the Giant Hogweed? Maybe its because the sap from the plant can cause burns. “It reacts with the sunlight and it actually burns a hole in your skin,” said Pennsylvania Department of Agriculture Weed Scientist Melissa Bravo. The root has been known to burn the lips of goats that try to eat it.

The Giant Hogweed is native to the Caucasus Mountains and was brought over by immigrants in the first part of the 20th century as a decorative plant and a reminder of home. In 1980 it was designated by the federal government as a noxious weed because of its ability to rapidly spread and crowd out other native plants. A similar designation was made in Pennsylvania in 2001.

When the plant went on the state’s noxious weed list an eradication program was launched. "Nearly 80 percent of the known Giant Hogweed sites have been eradicated, thanks to the effective teamwork between the U.S. Department of Agriculture, our state agriculture department, and property owners statewide," said state Agriculture Secretary George Greig. "While we must remain vigilant, the goal of completely eradicating the invasive weed is achievable."

Over the years, nearly 600 Giant Hogweed sites have been confirmed in Pennsylvania, with more than half located in Erie County. There are now 133 active sites in the state. The closest patch to Pittsburgh is along a set of train tracks in Evan’s City, Butler County. “We think a flower was caught by a train and tumbled along the tracks spreading its seed’” said Bravo.

The seeds from the plant can remain viable for as many as three years before geminating. Making it even harder to eradicate is the fact that according to Bravo it can still be a while before you realize you have a Giant Hogweed growing. It remains small for as much as three years before putting out the three-foot wide leaves, stalk the size of a 7 foot length of PVC pipe and flowers with a 15-foot diameter.

Bravo and her team return to known sites several years in a row before declaring victory. The state continues to do battle yearly with the weed along Little Kettle Creek in Potter County and Le Buff Creek in Erie County. The 10,000 seeds produced by each flower can be carried downstream. “Every river and creek in impacted in Europe,” said Bravo.

Bravo believes the state will eventually eradicate the plant from all 67 Pennsylvania counties. Among the other plants on the state's noxious weed list is Multiflora Rose, Canada Thistle and Kudzu. The state is trying to eradicate the Kudzu but has given up on the rose and thistle due to their range.

(Photo courtesy PA AG. Dept.)