Home & Garden

Sure, these trees you see all over are pretty, but they’re causing some big problems

Bradford pear trees offer visual appeal, but are highly prone to splitting.
Bradford pear trees offer visual appeal, but are highly prone to splitting. TNS, file

Recently, a reader wrote to the Centre Daily Times that their neighbor experienced several flat tires on his farm machinery this summer while making hay in fields around his Boalsburg farm. Thorns/spikes on branches of small seedlings and saplings that are invading the hay fields are evidently the cause of the damage.

Now, what is causing this problem was the next question.

Research on the internet pointed the reader to the “Bradford” pear — yes, those white blooming trees you see everywhere in the springtime, especially in developments around town. What they found out was that all those white blooming trees are now an environmental disaster happening right before our very eyes.

As reported at the Charlotte, N.C.-based WCNC, it seems that just about every white blooming tree in the springtime — with only the exception of wild plums, which is a short multi-flora tree that seldom reaches over eight feet in height — are an ecological nightmare, getting worse and worse every year and obliterating our wonderful native trees from the rural landscape.

This especially applies to that “charming” Bradford pear that has been planted along many grass strips between the roadway and the sidewalk or in the middle of your front yard. It seems that the Bradford pear is worse than kudzu (I have seen that in North Carolina climb over abandoned buildings), and the problem seems to be progeny of Bradford pear.

According to WCNC, when the Bradford pear was first introduced as an ornamental in 1964 by the US Department of Agriculture, it was known then that this tree possessed the weakest branch structure in nature. Anyone who has seen Bradford pear trees after an ice storm knows what I’m talking about. I remember the ice storm in Park Forest more that a few years ago. Also, the tree was assumed to be sterile. Bradford pears will seldom last more than 20 years before they bust themselves apart at the seams.

In an attempt to extend the lifespan of this tree, other varieties such as Cleveland Select, etc. were introduced. These trees will now live for about 25 years. After 25 years, WCNC reported that the ill effects of the steep v crotch branch structure — which all pears possess — take their inevitable course of action and cause pear limb structures to crack, split and bust.

“However, the fact that Bradford pear trees are short lived and dangerous is not the real reason that these trees are such a disaster. The problem is that these trees are in fact not sterile. No two Bradford pears will ever reproduce among themselves, but they do cross pollinate with every other pear tree out there, including the Cleveland Select pear trees that were meant to be the salvation of flowering pears everywhere,” the WCNC article states.

The introduction of other newer pear varieties has compounded the problem to the point where it is almost too late to clean up the problem. Because of the cross-pollination problem, pear trees have now proliferated exponentially across our environment. To make matters worse, the progeny have reverted to the ancient Chinese Callery (Pyrus calleryana) pears which form impenetrable thorny thickets that choke out the life out of pines, dogwoods, maples, redbuds, oaks, hickories, etc.

When you now see fields of white flowering trees, what you are actually looking at are Callery pears destroying nature. Callery pears do have 4-inch thorns. They can’t be mowed down. These thorns will indeed puncture your tractor tires.

So you can now see the problem that Bradford pear has caused. And if you don’t believe that, just take a little ride, and notice all the white flowering trees blooming in the springtime. The closer they are to “ornamental” Bradford pear trees, the thicker they are, as our reader’s neighbor can attest to.

If you ever go visit a plant nursery and want to know if it is a good nursery or not, ask if they sell Bradford pears. All reputable nurseries are well aware of the evils of this tree, and refuse to sell them. I checked with Jim Sellmer, professor in the plant science department at Penn State, and he said the industry has been working for years through breeding to find better Callery pear cultivars with better branching patterns, less fruit, and smaller fruit.

Bradford is indeed an old cultivar that is not sold by good nurseries. Cultivars like Cleveland select with better but not great branching and considered less fruitful were the standards when Sellmer started working back in the day. He said that he has a couple of newer cultivars in the Schmidt trials at the farm that still fruit but not as heavy.

Bill Lamont is a professor emeritus in the department of plant science at Penn State and can be reached by email at wlamont@psu.edu.