"Those blasted Bradford Pears! If I had a chain saw, I'd fire it up and cut down every one in the entire state."
She passed around for our inspection a black thorny branch she had taken from one of the offending trees and described the dense thickets she had seen in her area. She viewed these pear trees as thorny monstrosities that shaded out and choked out all plant life below them; trees that nurtured no beneficial insects and whose non-nutritious fruit could be eaten by birds whose droppings would spread the evil spawn for miles around.
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| Honeylocust |
My fellow Nits (naturalists in training) oohed and aahed over the prickly branch, but when it got to me, I was unimpressed. My reaction was in part moderated because we have on our property (and treasure!) a honeylocust tree that is the most dangerously thorny thing I have ever seen. The callery pear trees reviled by our speaker have smooth trunks and relatively thornless branches, but the honeylocust is better armed than a porcupine. The thorns on its trunk and branches form 3-dimensional clusters so that no matter how they fall to the ground some thorns will be facing up. Unlike the callery pear, the honeylocust frequently sheds dead branches and clusters of well-concealed thorns. Thus, walking beneath a honeylocust tree (or even parking a car beneath one) is a bit like wandering into a minefield. I have shoved honeylocust thorns right through the soles of my tennis shoes on many occasions. I once incautiously knelt down to observe a pretty wildflower and drove a honeylocust thorn right into my shinbone--a memory that can still bring tears to my eyes. That puncture wound swelled up like a golf ball, and even after healing remained a palpable knot beneath the skin for several years. I love a good honeylocust tree for its incredible ferocity; it is a savage tiger of a tree. By comparison, the callery pear is a sweet little kitten. And the Bradford pear (a special cultivar) is even more tame, being entirely thornless and usually infertile.
Indeed I quite like Bradford pear trees. One reason for this is that I have long experience with them. I planted two tiny Bradford pear saplings by my pond more than twenty years ago (long before assertions about their invasive nature began to be promulgated). Those two saplings have grown into handsome trees. Each spring they are the first trees to burst into bloom and each fall their colors are the most beautiful and the most long-lasting. The authorities certainly do label the trees as nonnative and invasive, but religion relies on reference to authority. Science relies on observation and experimentation. In the remainder of this article I will consider the charges against the tree and share my observations.
1. Bradford pears are nonnative. This is true. But all pear trees in America are nonnative, having been brought by European settlers in the 17th and 18th centuries.
2. The Bradford pear is a cultivar of the thorny callery pear. This is true, too. But it is important to note that Bradford pears have been bred to be thornless and infertile and that most fruit pears are grafted onto callery pear rootstock. Fruit pears are much more susceptible to fire blight than Bradford pears, and when the graft dies, the rootstock usually flourishes and grows up into a callery pear. Thus, one should not assume that the thorny pears one sees are the result of unintended propagation from ornamental Bradford pears. Fruit pears are the more likely culprits.
3. Birds will eat the fruit of Bradford pear trees and can therefore spread the seeds through their droppings for miles. This is true, but so what? That birds are nourished by the fruits of the Bradford pear is a very good thing. Their droppings contain these seeds as is the case with any other fruit that nourishes birds. Normally those seeds are infertile, but it is said that cross pollination of different callery cultivars can produce fertile seeds. Later in the year I will try to test this hypothesis with the seeds from my own trees.
4. Bradford pear trees are invasive. This is certainly untrue of the Bradford pear cultivar, but it is possible that fertile callery pear trees can form dense invasive thickets. There is testimony to support that. But a plant that is invasive in one region is often not invasive in another. Since pear trees bloom and leaf out so early in the spring (and retain colorful leaves so late in the fall), this something that one can easily test by observation. I have been driving all over Baxter County, Arkansas, this spring and I have been on the lookout for problem areas. Nowhere have I seen invasive thickets of Bradford or callery pear trees. There is an abandoned amusement park that has an abundance of wild pear trees, but it is not so dense as to be a thicket, nor is it a monoculture. I hypothesize that the thin, rocky soils of the Ozarks are not so hospitable to these trees as richer soils.
5. These nonnative species do not support insects and birds. This is completely false. Because they are the first trees to blossom in the spring, our Bradford pear trees absolutely hum with the buzzing of honeybees and pollinators of all kinds. At dusk the moths flutter in clouds seeking the nectar. We own four acres of land, nearly all of which is left in a natural state. We have wild plums, wild peaches, redbuds, hackberries, sugarberries, wild cherries, dogwoods and more. But these two Bradford pear trees seem especially prized because of their role as the heralds of spring. Here is an early Bradford pear leaf that has been thoroughly munched by a caterpillar. Here is a caterpillar in action . . . and again a much magnified caterpillar . . . and on my thumb to give a sense of its tiny size. Here is a spider making its home on a pear leaf. Here is a Crane fly in close proximity with what seem to be two spiders! Here is a spider that has spun its web on a pear leaf and captured three insects. In the winter rare yellow-bellied sapsuckers sometimes stay nearby specifically so that they can take advantage of these two Bradford pear trees. They drill dense patterns of holes in the trunks and then return frequently throughout the day to dine on the insects attracted by the sap. No other trees on our property are used by the sapsuckers in this way.
Because I now have good friends who disapprove of Bradford pear trees, I would not plant them again. But I do cherish the ones that I have and I hope that thoughtful naturalists will reconsider the contributions of these ornamental trees to the environment (at least in areas where they are not invasive). . . . Oh, and as to the white flowering trees in the photo at the top of this blog . . . those are American Dogwoods, native trees that propagate profusely as a result of seeds in bird poop, trees that leaf out early and shade out their competitors, trees that frequently dominate the understory in this part of the Ozarks. Delightfully so!
