These fast growing pear trees are choking out native ecosystems
Keep Indianapolis Beautiful offers guidance on native landscaping
Keep Indianapolis Beautiful Director of Native Landscapes Ethan Olson talks about benefits and possibilities of native landscaping.
Kelly Wilkinson, Indianapolis Star
Indiana has rich biodiversity with thousands of species in unique habitats, but the ornamental plant trade, globalization and development have introduced new threats to these ecosystems. IndyStar is highlighting some of the invasive species putting our natural landscape at risk and how you can help combat their spread.
Tree breeders on an agricultural mission brought the unassuming Callery pear (Pyrus calleryana) tree into the United States in the early 1900s. They planned to breed the species with vulnerable pear crops in the Pacific Northwest to create a new tree resistant to a deadly fungus threatening the industry.
They succeeded and then some. What ensued has become a widespread ecological disaster. The resulting pear trees have spread far and wide from where they were planted, stifling native biodiversity every step of the way.
Decades ago, the oblivious horticulturist who spotted one of the pears growing near a United States Department of Agriculture research station in Maryland thought it might be a nice adornment for American cities, streets and lawns. With its soft, fluffy spring blooms and vibrant red colors, the tree was an aesthetic masterpiece.
From the original Callery pear, horticulturists bred a consumer-friendly variety: the Bradford pear. It lacked thorns and was hypothetically sterile — perfect for homeowners looking for small, manageable trees that wouldn’t prove too unwieldy.
“It was very, very heavily planted because they grow fast, and they are cheap,” said Ellen Jacquart, a retired botanist and president of Monroe County – Identify and Reduce Invasive Species. “And they have pretty flowers in April. All of that conspired together to make people plant just millions of them.”
Now, native ecosystems are dealing with the fallout from the pear trees’ success.
Callery pear, everywhere
Bradford pears are not completely sterile, horticulturists later discovered. When other varieties are planted nearby, the trees can cross pollinate and send fertile seeds out to grow nearby.
The trees that once just speckled the landscapes where they were deliberately placed have now invaded state highway berms, fields, forests and wetlands. In Indianapolis, planted prairies that once boasted native grasses and flowers have been consumed by Callery pear trees and their relatives. In wooded areas, the species is invading the understory, crowding out native plants and biodiversity.
Biologists have one simple wish.
“Please cut them down,” wrote Dawn Slack, the Indiana Invasives Initiative coordinator for the State of Indiana Cooperative Invasives Species Management, in an email to IndyStar. “To be frank, if we continue to adorn our landscapes with invasive plants from other countries (in essence celebrating the natural beauty of other countries instead of our own), then we are negatively impacting this country.”
When invasive species run rampant, these intruders can outcompete native plants and shrink the food supply for insects and animals.
The one good thing, according to Slack, is despite having caused the issue, humans are part of the solution.
In Indiana, programs to fight back against invasive species like the Callery pear abound. Hamilton County residents can qualify for free native trees when they remove invasive species like the pesky pear trees, and the city of Carmel is working to keep the species from crowding out its urban forest.
To learn more about how you can get involved with removing invasive species in Indiana, contact your regional specialist at the State of Indiana Cooperative Invasives Species Management.
IndyStar’s environmental reporting is made possible through the generous support of the nonprofit Nina Mason Pulliam Charitable Trust.
Sophie Hartley is an IndyStar environment reporter. You can reach her at [email protected] or on X at @sophienhartley.
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