Spring is a time for blooming plants and flowering trees. But word to the wise: some of those beautiful blooms might come from invasive species.
One such plant is the Bradford pear, a tree covered in attractive white blossoms with some unattractive features. What was once considered an ornamental and low maintenance decoration for yards and parks has proven detrimental to native plants and has even been banned in some states.
The trees “have little to no value to wildlife and displace native trees,” said Steven Long, assistant director of the department of plant industry at Clemson University in South Carolina. Other problems? Their thorns can puncture vehicles tires and their blooms stink, Long said.
Where did the Bradford pear tree come from? Why is it dangerous to native plants? How do homeowners get rid of it? Here’s what to know about this invasive plant:
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What is a Bradford pear tree?
The Bradford pear, also known as the “Callery” pear, is a popular ornamental tree native to Asia and found throughout the eastern US It is most commonly planted in South Carolina.
“They’re in suburban and rural areas, as well as in natural forests,” Kelly Oten, assistant professor of forestry and environmental resources at North Carolina State University in Raleigh, said.
The tree is perhaps most famous for the scent of its blooms, which some have compared to rotting fish, urine and baby poop. The fragrant white blooms that appear in early spring draw admirers, despite the offensive smell.
Where did they come from?
The trees were introduced by the United States Department of Agriculture as ornamental landscape trees in the mid-1960s. They became popular with landscapers because they were inexpensive, transported well and grew quickly.
Considered a sterile hybrid, plant experts did not think the tree would propagate out of control, but scientists developed smaller hybrids designed to compensate for the Bradford pear’s weak branch structure.
The trees cannot self-pollinate, but can reproduce with another variety of the Pyrus calleryana species. The offspring are called Callery pears.
The resulting hybrids are even more problematic than the original Bradford pear tree.
Are Bradford pear trees harmful?
And it is. The trees choke out other plantsparticularly in fallow fields, or empty tracts of land seen as future forests. They can grow to 30 feet tall and the “dead zone” beneath its dense canopy keeps light from reaching other plants.
Because they bloom earlier in the spring from March to mid-April, Bradford pears overtake resources from surrounding native species.
Long said the trees also increase the cost to maintain land.
“They reproduce prolifically in (once-landscaped) areas and tend to dominate small lots as they are of the first to emerge once a lot is no longer being mowed,” he said.
“Callery pears are like a food desert for birds,” Oten said. “Caterpillars, which are especially important in the spring when mother birds are getting soft-bodied insects to feed their young, don’t feed on them. Because there are no caterpillars that feed on the Bradford pear, there’s nothing for them to eat there .”
The trees “break easily during ice and wind storms which we have plenty of in (South Carolina),” Long said.
Researchers discovered in the ’80s that the tree has a fragile composition. Its signature “steep v crotch” means the tree has a weak structure at the “V” of the branch, yet is stronger in other directions so that it snaps off in areas from old age and high winds.
Drivers should avoid parking their cars beneath a Bradford pear.
Where is the tree banned?
South Carolina has enacted to ban on new Bradford pear sales effective on Oct. 1, 2024. A ban on the sale and cultivation of the tree in Pennsylvania will also take effect in February of that year.
The tree was placed on the invasive species list in Ohio in January 2018, meaning in-state nurseries and landscapers must phase out selling the trees over the next five years.
Experts say all native species in South Carolina will struggle as long as the Bradford pear tree survives. Even other trees that are not threatened for survival, such as oaks, maples and hickories, are being out-competed.
Bradford pears in South Carolina:Methods of attack range from bounties to bans
“I expect many more states will soon follow Ohio and South Carolina’s lead on this,” Long said.
How can you get rid of a Bradford pear tree?
At 20 years, the lifespan of a Bradford pear is relatively short, but the species might have reached its tenth generation of production.
“When they cross with another pear and become wild, the offspring does have thorns. This can make it difficult to remove,” Oten said.
The thorns are sharp enough to puncture tires, making it difficult to mow down a field of Bradford’s.
Fire and some herbicides are alternative options for elimination, but fire has been shown to aid resprouting.
The best weapon, according to experts, is to cut down the trees, and some states are providing incentives for removal. Clemson University in South Carolina has offered to exchange five cut-down Bradford pears with native trees.
The North Carolina Forest Service Urban and Community Forestry Program advises people to remove or treat the stump with an herbicide to prevent it from sprouting new trees and to grind down the stump before placing a new tree in the same spot. Some landscaping companies provide stump-grinding services, according to the program.
Most importantly, homeowners should avoid planting the tree altogether and instead plant native species.
“We have plenty of native trees that have very similar blossoms, such as the flowering dogwood, black cherry, and serviceberry,” Oten said.
Reach out to Chelsey Cox on Twitter at @therealco.
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George is Digismak’s reported cum editor with 13 years of experience in Journalism