In addition, the root stock can send up sprouts. It turned out that, although trees of the same variety cannot produce seeds with each other, two different varieties within a pollinator's range can produce fruit that squishes on sidewalks and feeds starlings and robins, which spread the seeds widely. "They're kind of a food desert for a bird," said Coyle, who leads Clemson's annual "Bradford pear bounty," providing native saplings to landowners who have felled their Callery ornamentals. And their bug-resistant waxy leaves mean insect-eating birds don't come near them. Their adaptability is one reason they're so invasive. Now, the USDA describes Callery pears as near ubiquitous and has been studying the best way to kill them. In 1971, the USDA even put out a brochure about their care, touting them as trees that bloom several times from spring through fall, thrive in many climates and soils, and don't attract plant pests. Genetically identical pears don't produce seed, so botanists figured the cloned varieties were safe for ornamental use. What mattered was that the plant was resistant to fire blight. Several, such as North Carolina, offer free native trees to landowners who provide photos proving they have cut down Callery pears on their property.įor the USDA, which ordered Meyer to send Callery pear seeds from China, the nasty spurs and marble-sized, inedible fruit were irrelevant. Some states, including Missouri and Alabama, are asking homeowners and landowners to stop planting them or to cut existing ones down and apply herbicide to the stumps. South Carolina, Ohio and cities including South Bend, Indiana, have banned or are banning all commercial varieties of Callery pears. Neither is Newport News, Virginia, which got rid of its Bradford pears in 2005. All are so pretty, hardy and insect-resistant that they were planted nationwide.īradford 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.īut the city is no longer planting them, Kastanis said. Other seedlings grew into 24 more ornamental varieties. That variety was commercially available by 1962, Culley and Hardiman wrote. By grafting its cuttings onto roots of other Callery pears, they cloned an ornamental line they named Bradford pears. In 1952, USDA workers noticed a spikeless mutant growing among Callery pears started from seed. history.Īnd, just as researchers had hoped, grafting edible pears onto Callery roots produced blight-resistant fruit trees. Hardiman wrote in a 2007 BioScience article about the plant's U.S. pear orchards, University of Cincinnati researchers Theresa M. Department of Agriculture National Agricultural Library, Special Collections, shows an unidentified man looking toward dwarf Callery pears growing in arid soil on a 2,000-foot-high mountaintop in China on March 31, 1917.Īt the time, a fungus called fire blight was devastating U.S. Meyer, an agricultural explorer who brought 2,500 species of plants including his namesake Meyer lemon to the USDA in the early 1900s, called the Callery pear wonderful, noting that it survived drought and poor soil. The trunks branch off in deep Vs, so after 15 to 20 years they tend to break in storms.īut Frank N. The stench wafting from the tree's billows of white blossoms has been compared to perfume gone wrong, rotting fish, chlorine, and a cheese sandwich left in a car for a week. Coyle, an assistant professor in Clemson University's Department of Forestry and Environmental Conservation. Seedlings only a few months old bear spurs that can punch through tractor tires, said David R. "If you mow it, it sprouts and you get a thicket," he said.
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