By Carl Parsons
With this post, the Sevier County Master Gardeners who man the SCAMGA Ask a Master Gardener Hot Line are introducing a series of articles based on some of the most interesting calls we receive. We begin with “The Case of the Callery Pear.”
Late last summer a client visited the Extension Office with a sample—branches cut from a small, shrub-like tree that he found on a vacant property he owned and wished to clear for development. “What are these?” he wanted to know. “They’re growing in a dense thicket on my property, and I need to get rid of them. And worst of all, they have sharp thorns on them.”
I removed the branch from the plastic bag with some difficulty for indeed it had numerous three inch long thorns that were exceedingly sharp and ripped the sides of the bag. But one look at the leaves identified the problem: Bradford pears gone wild!
When the USDA first introduced the Bradford pear in 1961, it was billed as the perfect tree—shapely, not too large, fast growing, and filled with white flowers in the early spring (never mind that they stink!)—a graceful tree that could be planted in yards and parks and along city streets. Also it was sterile, unlike the tree from which it was developed—the odious Callery pear (Pyrus calleryana).
The USDA even convinced Lady Bird Johnson to assist in a ceremonial planting of a Bradford at the agency’s offices in Washington, D.C. (I’ll bet it’s not there now!)
Growers and landscapers across the country quickly followed the USDA’s guidance and so began planting the trees everywhere. At first, the Bradfords were very impressive (as long as you held your nose in the spring). But as the trees started to age two problems developed.
The Bradford Pear – Unintended Consequences
First, the tree’s exceptionally soft wood could not support the weight of its branches, which had been trained to fork in order to achieve and maintain the tree’s nearly perfect round shape. At the forks of its branches the tree’s soft wood eventually split. The bark opened up, water collected, rot began, and soon wind brought the branch down—and not a small branch like the ones we collect under maple trees. The Bradford’s broken branches might constitute as much as half the tree.
Second, the Bradfords are NOT always sterile, as the USDA claimed. Their lovely white (smelly) flowers sometimes produce a small hard fruit that animals carry away, eat, and effectively plant elsewhere. The resulting saplings are not Bradfords any longer, but the prolific, invasive, thorny pest that the USDA thought it had tamed— namely, the Callery pear. This is exactly what my client had found on his property, a dense thorny thicket of Callery pears.
So now what? The solution is straight-forward. Instead of “plant and enjoy,” as we were told to do with the Bradford, now we must CUT AND KILL the Callery. Yes, the solution is that simple: Cut them down AND kill them by painting the stumps with glyphosate concentrate (53.8% solution). Cutting alone will simply prompt the Callery to send up more saplings and produce an even denser thicket.
PS: Be sure to follow the safety precautions on the container label when using glyphosate.
PPS: This fall, as I was cleaning up my pollinator garden, I found among the remnants of the cosmos and zinnias—a Callery pear!