The beautiful Bradford pear tree is in full bloom in northern Illinois. But what's that smell?
Spring is a glorious time in Chicagoland. We emerge from the long winter, relieved to be outside in the sunshine again. Spring flowers are in bloom, and so are the flower-blooming trees. One of the most common of these in the Chicago area is the Bradford pear tree, also known as the Callery pear.
I have two of these trees, one in my backyard and one in my front. Most of my neighbors have one or more in their yards. They are all over my suburban neighborhood. They are everywhere.
Bradford pear tree in my backyard, photo by author
And when they bloom, along with all of those gorgeous white flowers comes a sickening smell. When you step outside on that first morning when they have emerged, you know before you see the tree that it's blooming.
You know because there is a strong whiff of rotten garbage wafting through the air. Rotten garbage mixed with dead fish. It's not a subtle smell either. It's quite strong.
And now, I notice these trees are not just planted in my neighbor's yard, but growing freely in the natural areas that border the grassy field near my house. As it turns out, Bradford pears are not only stinky, but they're an invasive species as well.
Experts at the Morton Arboretum in Lisle warn Illinois residents against planting Bradford pear trees. According to their website, the trees, "can self-sow fairly readily and has become aggressive in some areas due to this."
Another problem listed by the Arboretum, "Callery [Bradford] pear has a weak wood and branch structure and is susceptible to ice storm damage."
Common sense would tell you, it's not a good idea to plant a tree that can't withstand an ice storm in a Chicago suburb. And yet, they are frequently found throughout northern Illinois. A non-native species originally from Korea and China, the tree thrives in our climate, preferring moist, well-drained soil. But it can tolerate occasional drought.
It also has a strange little fruit that drops from late summer to fall. My dogs are obsessed with eating those fruits and it does no favors for their digestive system.
While researching this article, I discovered that the seeds are toxic when ingested in large amounts. They contain cyanogenic glycoside, which turns into cyanide when broken down or consumed.
Apples and the pears we eat also have seeds containing cyanogenic glycoside. But we tend not to eat the seeds of those fruits, and if you accidentally ate a few, it wouldn't be enough to poison you. But the Bradford pear has a large seed-to-pulp ratio, which means it's easier to eat the seeds in this fruit.
However, an adult human would have to eat a lot of them to be poisoned; which is very unlikely since the fruits are so small, brown, and hard. But a small dog or even a child might be able to eat enough to cause some trouble. The bottom line, I need to do a better job cleaning up the fruit from this tree in the fall before my pugs forage for it.
Blooming Bradford pear trees at a park in Plainfield, IL, photo by author
According to the Clemson Home and Garden Information Center, the Bradford pear tree situation is even worse than the smell and the strange fruit. These trees were bred to be sterile and were introduced to the U.S. as an ornamental tree. But they turned out not to be sterile.
They cross-pollinate with other varieties of Callery pear trees. Birds eat the fruit and spread the seeds everywhere. The trees begin to grow on the edge of fields and abandoned lots. These cross-pollinated, wild trees have thorns as big as 2 inches long, and they can damage equipment as you try to remove them from the land.
Due to their thorns, they are a huge problem for farmers. And similar to the invasive nature of kudzu in the South, they can choke out hardwood trees and other native plants.
To make matters worse, their lifespan of the tree is only about 15 to 20 years. This means the two trees in my yard may not survive the next ice storm. At least when it is time to replace them, I'll know enough to avoid the Bradford pear.
Blooming Bradford pear tree in a Plainfield, IL neighborhood, photo by author
If you have a tree species you are considering, you can get information from the Morton Arboretum before you plant. Things to look for are its hardiness rating for the Chicago area and its resistance to disease and pests.
For an idea of a small, hardy ornamental tree for your yard, check out this list from the Chicago Botanic Garden.
Don't make the same mistake my husband and I made and buy the first tree you see at the garden center because you like the picture on the tag. Do your research before you end up with a trash-smelling (although very pretty) nuisance in your yard.