Wednesday, December 8th 2021, 10:30 am - The plant was introduced to the U.S. in the 1960s as a sterile hybird, but has begun to cross pollinate.
The Bradford pear tree was intentionally brought to North America from Asia in the 1960s, introduced by the U.S. Department of Agriculture. For decades, it has served as a popular ornamental tree, prized for its early spring blooms of delicate white flowers and long-lasting colours in the autumn.
When Bradford pears were first planted, they were thought to be sterile hybrids - but cross-pollination has helped the tree migrate into natural spaces, where it outcompetes native plants.
Another thing: the blooms are incredibly smelly, with some people comparing the scent to rotting fish.
Officials in South Carolina plan to prohibit the sale and purchase of the tree by 2024, and botanists are looking into ways to kill it. They've placed a bounty on Bradford pears, offering compensation to anyone who successfully removes a tree.
They're also launching educational programs to teach the public about the dangers of Bradford pears and the benefits of planting native species.
“We’re trying to get people to plant more native things in their yards that won’t become invasive on the landscape,” Clemson University forest health specialist David Coyle said in early 2021.
“If you want something with pretty flowers in the spring, there are plenty of native options. If you want bright red foliage in the fall, there are native trees and shrubs with awesome-looking fall foliage, too.”
Bradford pear trees are known for their delicate white flowers. Stylized image by Cheryl Santa Maria. Blossom: RiverNorthPhotography/Getty Images Signature.
In the 1980s, scientists discovered the trees were prone to breaking from high winds, or weakening at a certain age - they'll often 'kill' themselves around the 20-year mark. This is due to a weak branch structure called a "steep v crotch." But while the trees are weak at the "v" point, they remain strong elsewhere, making the falling branches a safety hazard, especially for cars parked underneath.
In the wild, masses of snapped branches can create a dead zone that blocks out the light other plants need to survive, Coyle told USA Today.
Scientists compensated for the weak branches by developing similar trees that weren't as susceptible to breaking. Those trees interbred with the Bradford pears, creating an invasive hybrid capable of reproducing.
Bradford pears are cross-breeding with other native pear trees as well.
"Because of the cross-pollination problem, pear trees have now proliferated exponentially across our environment. And, to make matters worse, the evil offspring has reverted to the ancient Chinese Callery pears which form impenetrable thorny thickets that choke out the life out of pines, dogwoods, maples, redbuds, oaks, hickories, etc.," Durant Ashmore of the Greenville News wrote in 2019.
"When you see those fields of white flowering trees, please don’t get giddy with excitement over pretty white flowers. What you are looking at are Callery pears destroying nature."
Video production: April Walker.