Like so many regions in New York, nearly every corner of Missouri has been hit hard with the invasive spread of Callery pear (Pyrus calleryana spp.). Callery pears are self-sterile, but it turns out they readily cross-pollinate with other cultivars. Also, the rootstock upon which a Bradford pear is grafted will sometimes sprout, eventually yielding flowers and viable pollen.
Fortunately, Missourians are often out in front with innovative approaches to urban forestry and invasive plant control. Here’s how they reduced the number of Callery pears and increased the use of native, non-invasive trees. Special thanks to Tina Casagrand of the Missouri Invasive Plant Task Force (MoIP) for her help with this post.