One of the most lovely heralds of spring are the cottony white blooms of the Bradford pear trees. In full splendor on a mature tree, they've been likened to white clouds. They certainly make a showy impression.
But there's a much bigger story behind Callery pear trees or Pyrus calleryana. Native to Korea and China, Callery pears were imported to the U.S. several times. Originally, it was to help with issues facing the common pear, but then the tree was embraced as a popular ornamental, especially the Bradford cultivar. When the tree was introduced in 1960, people loved it. “Few trees possess every desired attribute, but the Bradford ornamental pear comes unusually close to the ideal,” a New York Times reporter gushed. Callery pears now are found throughout the Eastern U.S. from New Jersey to Illinois and south to Texas.
Although the flowers are pretty, they are relatively short-lived ... as are the trees. They tend to have a weak branching structure, which means they split and break easily, especially in strong winds and storms. When they come crashing down, they can do a lot of damage.
The trees are also incredibly invasive, forming dense thickets that crowd out other plants, including any native species that can't compete for soil, water and space or tolerate the shade. The tree's seeds can be spread by birds and possibly even small mammals, causing Bradfords to pop up in places they were never intended to be.
According to the University of Georgia College of Agricultural & Environmental Science:
If lawn mowers or weed eaters damage the grafted crown, the fertile rootstock can produce suckers that can grow, dominate and produce fertile fruit. Trees that are cut and removed due to storm damage can sometimes regrow from the stump. The resulting tree from the rootstock can also produce fertile fruit. These and other factors may have contributed to the trees seeding out into natural areas and becoming an invasive problem.
A smellier issue
But the invasive, fragile plants have even one more unpleasant quality: They stink. The smell of the trees in full flowering mode has often been compared to rotting fish.
If you already have a Bradford pear, careful pruning won't help the smell, but it should help your tree grow stronger and live longer. If you've only been eyeing the pretty blooms and have yet to plant a Bradford, the National Park Service (NPS) has some strong advice: "Do not plant Callery pear or any cultivars including the well-known Bradford pear."
NPS suggests hardier, non-invasive substitutes such as common serviceberry (Amelanchier arborea), Allegheny serviceberry (Amelanchier laevis), cockspur hawthorne (Crataegus crus-galli), green hawthorne (C. viridis) and the native sweet crabapple (Malus coronaria). Or ask for suggestions at your local extension service or garden center.