Callery Pear Pyrus calleryana

Basic info - The Callery pear is a medium deciduous tree that flowers in early spring and produces small fruits in fall. It was introduced to the US from China and Vietnam as an ornamental tree in residential and commercial developments in the 1960's. Initially, it was thought to be sterile, but it was later discovered to be able to outcross with other pear varieties and produce fertile seeds. 

Impacts - This tree spreads rapidly through producing lots of fruits which are very attractive to birds and other small animals, distributing the seeds  which germinate and grow very quickly, establishing dense thickets that are extremely difficult to remove. In these packed stands, native plants are out-competed for water, soil, and space, which is worsened by the tree's ability to release chemicals into the soil that suppresses other plant species. The Callery pear doesn't have many natural controls, such as insects and disease, which also helps it colonize sizable areas within just a few years. Mature trees also tend to form woody thorns, which can puncture shoes, tires, and make the thicket impenetrable to humans and animals. 

Identification - The Callery pear ranges from 25 to 50 feet in height. Its branches may have thorns, and its leaves are dark green, round, waxy, and up to 3 inches in length. Its flowers in the spring are white, have 5 petals, and occur in clusters. Their aroma is offensive, sometimes described as rotting fish. In the fall, this tree produces pears that are tiny, brown, and woody. 

What can you do to help? - If you've identified a Callery pear, or think you might have but aren't sure, you can report your discovery on the EDDMapS (Early Detection and Distribution Mapping System) app or website, or upload an image of it to the iNaturalist app. 

Seedlings can be pulled from the ground by hand, but once the tree is a few years old, it must be cut down and herbicides must be used on the stump. Learn more about control options for invasive trees here. 

You can also plant a number of native alternatives to the invasive Callery pear, such as Serviceberry, Flowering dogwood, Eastern redbud, and many more. Read about these and additional alternatives here.