Callery pear

Tracking a rotten renegade

Callery pear, Pyrus calleryana, has become an aggressive invasive species in many parts of the Midwest and eastern United States, outcompeting native trees and forming dense monocultures. And though this non-native species may have pretty flowers in the spring, they sure smell terrible!

Callery pear infestation in Connecticut. Photo by Anne Arundel, Chesapeake Bay Program.

How you will help

Early detection is key to controlling new invasive species. You can help researchers, land managers and policymakers generate data on the distribution and density of Callery pear by reporting sightings in iNaturalist.

Callery pear has been reported in Minnesota 26 times on iNaturalist and they all appear to be cultivated plantings. We'd like to better understand where it is and if it's moving to untended lands in Minnesota as it has elsewhere.

iNaturalist Callery pear reports in Minnesota as of March 18, 2024.

Using iNaturalist

Watch this 1:24 minute video to learn how to report to iNaturalist. 

If the tree is tended, like in a yard or park, please click the "It is captive or cultivated" choice in the iNaturalist report. 

If you are an EDDMapS app user and find Callery pear in untended natural areas, please also report it in EDDMapS.

Callery pear identification

Watch this 3:53 minute video from Penn State Extension for an overview of Callery pear identification. 

Then review the images below to see the differences between Callery pear and common look-alikes.

Callery pear flowers

These are likely to be the very first blooms in the spring. The 5 petaled white flowers commonly smell like vomit, rotting fish or wet animal waste. Photo by A. Gupta in Rochester, MN.

Crabapple flowers look similar

Apple trees likely bloom about a week later than Callery pear. The flowers look very similar but apples blooms smell wonderful. Photo by Howard F. Schwartz, Colorado State University, Bugwood.org.

Callery pear bark: brown and furrowed

Photo by Chuck Bargeron, University of Georgia, Bugwood.org.

Apple bark: grey and flaky

Photo by Becca MacDonald, Sault College, Bugwood.org.

Callery pear is on the Minnesota Noxious Weed Specially Regulated Species list. Starting in 2023, there is a "three-year production phase-out period, after which sale of this species will be prohibited and the species will be designated as Restricted in 2026."

All questions about this project should be directed to Angela Gupta, UMN Extension Forester, agupta@umn.edu