The Callery Pear was initially brought over from China in the early 1900's to help develop a more disease resistant fruit bearing pear tree. The unexpected result was the Bradford Pear; an ornamental pear which could tolerate a multitude of tough growing conditions. Heralding spring with their snow white blossoms they soon graced city streets and homes across America- until a major flaw became evident. Fast growth, a narrow crotch angle and heavy branches provided a recipe for disaster. Bradford Pears soon became famous for their tendency to split during storms and the inability to recover their signature shape.
New improved cultivars appeared on the market but once again there was an unfortunate consequence. While Bradford Pears were sterile, the new cultivars had the ability to cross pollinate with their cousins. Together they produced small fruits- unpalatable to humans but tasty to birds. Soon these hybrid pears were showing up everywhere. Even worse the wild child seedlings had inherited the ability to thrive under tough conditions and were also capable of producing sharp thorns like their exotic parent making them both prolific and painful to remove.
These issues have induced many to remove what was once considered a dependable landscape choice. Many cities including Champaign have banned Callery pears from city plantings. Homeowners may still purchase and plant them however they are currently under observation and may one day appear on the official Illinois invasive species list.
Alternatives to Callery pears include redbud, service berry, dogwood and many more. Visit a reliable source like the University of Illinois http://urbanext.illinois.edu/treeselector
Morton Arboretum http://www.mortonarb.org/ or
Missouri Botanical Garden http://www.missouribotanicalgarden.org/plantfinder/plantfindersearch.aspx to research your choices. Ideally you will find a tree you will enjoy for many years.