Callery Pears: an Invader ‘Worse Than Murder Hornets' Spreads to 30+ States
He and his 17-year-old son have cut down an estimated 1,400 Callery pears, applying herbicide to the stumps. But he figures there are about 1,000 more to go.
At the time, a fungus called fire blight was devastating U.S. pear orchards, University of Cincinnati researchers Theresa M. Culley and Nicole A. Hardiman wrote in a 2007 BioScience article about the plant’s U.S. history. Bradford and other Callery ornamentals are the third most common trees of 132 species planted along New York City streets -- more than 58,000 out of 650,000 as of 2015, the most recent count, said city parks department spokesman Dan Kastanis.
Genetically identical pears don’t produce seed, so botanists figured the cloned varieties were safe for ornamental use.