I think many people are well aware that the Bradford pear, Pyrus calleryana ‘Bradford’ is not a desirable landscape tree. It has a very weak branching pattern and has a tendency to split apart, even at a relatively young age. For those of you in the northeast who recently endured the freak October snowstorm, this characteristic was painfully apparent and dramatic. Some of the Bradford’s looked like they’d been struck by an artillery shell, leaving a splayed pile of branches and a stump.
Introduced by the National Arboretum in the 1960s, the tree has persisted in the trade much longer than it should have. On the positive side of a ledger the tree has glossy green leaves no insect pests, great fall color, a compact uniform habit and tolerance of urban conditions. I was warned about the trees bad habits in the early 1980′s, and I personally never liked the tree very much. But if I had an insistent client, I usually directed them to an improved cultivar such as ‘Aristocrat’ or ‘Chanticleer’, which with a stronger central leader were reportedly more resistant to splitting.
The Callery pear is listed on many invasive plant lasts. In the past year or so, I have begun to notice abandoned fields, in an early stage of succession, with thousands of pear seedlings. The colonization has been extremely aggressive, with a near monoculture created in five years or less. The pears retain their colorful if leaves well into November and are it easy to spot in the landscape.
Since the Bradford’s have been around for quite some time I wondered why, at least my area, they suddenly seem to be a problem. As it turns out, the Bradford pear is a self sterile cultivar, producing few if any viable seeds. So far so good. Introduce the new improved cultivars as pollinators and voila! We have viable seeds readily dispersed by birds.
Needless to say, just stay away from all Callery pears.