6 March 2024
As warm weather returns to Kansas, so does a distinctive springtime odor that many liken to rotting fish. The overwhelming aroma is the result of an invasive species.
The Callery pear tree, which comes in multiple varieties, including Bradford pear, Autumn Blaze and Cleveland Select, is native to Asia and is now considered an invasive plant in the U.S. The tree, primarily grown for its appearance, was introduced to North America in the 1900s for agricultural use.
They can now be found in the eastern part of the U.S., “from New Jersey to Illinois and south to Texas,” according to Invasive.org, a project associated with the U.S. Department of Agriculture.
Characterized by its white flowers, the tree quickly became popular in landscaping due to its adaptability, color and shape, but the tree has become well-known for something else – its odor. The tree’s blooms typically have a strong unpleasant aroma, which can be likened to rotting fish or puke.
Kansas could become the next state to ban the tree. Ohio banned the Callery pear tree; Pennsylvania and South Carolina have passed similar bans that go into effect this year.
The tree poses a “major threat” to native grasslands and wildlife, according to the Minnesota Department of Agriculture. It can rapidly fill in gaps in open spaces, which leads to the trees crowding out native plants and disrupting ecosystems.
The tree was bred to be sterile and originally believed to be unable to reproduce. However, different varieties of the tree have cross-pollinated, leading to the spread of fruit-bearing trees.
“Its success as an invader results from its capacity to produce copious amounts of seed that is dispersed by birds and possibly small mammals, seedlings that germinate and grow rapidly in disturbed areas and a general lack of natural controls like insects and diseases, with the exception of fire blight,” as stated on Invasive.org.
Tiny, hard, brown pears appear on Callery pear trees in the fall. After they are softened by frost, they can attract birds that like to eat the fruit, according to the Minnesota Department of Agriculture. They are, however, inedible for people.
The tree’s messy fruit and weak branches are also among its undesirable qualities.