The Rampant Bradford Pear
It seemed like a good idea at the time...
For decades, the fields of Pyrus calleryana trees grown from seeds imported from China for research purposes were basically forgotten. In the 1950’s, with the post-war boom in housing and beginnings of the suburbs, horticulturists needed street trees that were basically weeds – that would grow in a variety of conditions and be free of pests.
Lo and behold, at the USDA Beltsville Maryland site a particular callery pear – loaded with flowers and with no thorns – was selected and thousands of grafted individuals were created and planted under the name Bradford pear. The Bradford pear is self-sterile and produced no viable seeds. But pears from the research fields with different characteristics – taller, narrower, etc., were also added to the trees planted and now pollination was possible. Birds and water moved these fertile seeds and new trees with dangerous characteristics proliferated.