By Jill Rebuck
Every April, a different kind of blizzard sweeps across Chicago-area neighborhoods. White blossoms line parkways in Naperville, commercial strips in Schaumburg, and front yards in Arlington Heights. It’s one of the most recognizable signs of spring and as of last fall, officially an invasive weed in Illinois.
But the beautiful Callery pear turned out to be an environmental Trojan horse. Also sold as Bradford pear, it has quickly become a nuisance. As of October 2025, it has been added to Illinois’ Exotic Weed Act, making it illegal to buy, sell, distribute, or plant in the state. Nurseries have been given a grace period to phase out existing stock, with the full sales ban taking effect Jan. 1, 2028.
Don’t worry. If you have a pear in the ground, you aren’t required to remove it. But this is a good time to take stock and assess what’s next.
How a ‘perfect’ tree became a problem
“The Bradford pear was the perfect tree on paper,” says Pat Etherington, certified arborist with The Davey Tree Expert Company in Lake Bluff. “It grew fast, looked great in spring, and handled tough urban conditions. For decades, it seemed like a win all around.”
The problem took decades to surface. The Bradford pear (Pyrus calleryana) was believed to be sterile, but as different Callery pear varieties were planted across neighborhoods, they began cross-pollinating. The resulting offspring are thorny and spread aggressively via birds carrying seeds into roadsides, prairies, and forest edges.
Now, those same qualities that made them attractive to landscapers are what make them so effective as invaders. They are aggressive, hard to remove, and displacing and harming native plants and animals. The Morton Arboretum in Lisle has documented Callery pear spreading throughout the region and noted that its thorny thickets crowd out native species.
The stakes go well beyond one tree. “People tend to think of a tree in their yard as just their tree,” says Etherington. “But invasive species don’t respect property lines. What spreads from your yard into a nearby forest preserve is a community problem.”
Illinois joins a national wave
Illinois is not alone. Ohio became the first state in the country to ban the sale of Callery pear trees in 2018. South Carolina, Pennsylvania, Massachusetts, and Minnesota, followed with their own bans. And as of January 2026, New Jersey has also banned the sale of these trees. The message from state governments across the country is consistent: the era of planting these trees is over.
What homeowners should do
For Illinois residents, the first step is simply knowing what’s in your yard. If you have a flowering pear tree, have a certified arborist assess its age and condition. Callery pears are notoriously prone to splitting, especially in ice storms or high winds. Planning a native replacement now means your landscape is ready when the time comes.
If invasive seedlings have already appeared on your property, look for thorny saplings with glossy, oval leaves along fence lines or naturalized areas, act quickly. Detecting invaders early and responding rapidly is essential to limiting their spread and the costs of managing them.
Learn which invasive species are present in your area and what local resources are available for management.
The good news: the visual appeal of the Bradford pear is achievable with native alternatives that support local wildlife. Etherington recommends several options for the Chicago-area landscape:
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