Tree of the Month, May 2023

Callery Pear (Pyrus calleryana)

by Martin (Mort) Schmidt for Simply Living

Callery Pear. Photo by Mort Schmidt.

Once considered the ideal landscaping tree, the Callery Pear cannot legally be sold, grown, or planted in Ohio, due to its invasiveness.

Callery Pear was introduced to the United States from Asia in the early 1900s. The edible Pear, Pyrus communis, was being devastated by the fire blight, and the disease-resistant Callery Pear was imported for possible use as a root stock. In the 1960s, interest in Callery Pear was rekindled for use in landscaping, due to its abundant white flowers, attractive fall color, lovely symmetry, and hardiness. But, as often happens, things didn’t work out as expected. 

Alternate versus opposite arrangements. Drawings by Mort Schmidt. 

Like most broadleaf trees found in Ohio, Callery Pear has alternately-arranged leaves and branches. The leaves are simple, i.e, they do not share a stem in groupings of 3, 5, 7, etc. The shiny oval leaves are approximately 1.5 to 3.0 inches long and have tiny teeth and no lobes. But the otherwise nondescript leaves are easily recognized by their wavy margins and their dark green summer and bright red autumn colors. 

Callery Pear leaves in summer and fall. Photos by Mort Schmidt. 

The conical to rounded trees typically reach a height of 50 to 60 feet and a trunk diameter of 10 to 12 inches at maturity. Immature bark is smooth and has small, elongated lenticels. Mature bark has shallow furrows. Saplings often have sharp spines hidden beneath leaves, that readily penetrate work gloves of the unsuspecting gardener. 

Immature and mature bark of Callery Pear. Notice the pointed spines on the immature tree on the left.
Photos by Mort Schmidt. 

The abundant flowers have five petals, characteristic of members of the rose family, and are white. The flowers are quite attractive, visually, but their odor is often compared to that of rotting fish. P. calleryana produces abundant small fruits that are relished by birds, who drop the seeds and propagate the trees far and wide. 

Callery Pear flowers and fruits. Photos by Mort Schmidt. 

Much of Callery Pear’s early popularity can be attributed to its hardiness – it prospered in acidic and alkaline soils, tolerated wet and dry conditions, and resisted diseases. But as the trees matured, they had a tendency to break and split. The original varieties were supposed to be seedless and spineless, but when split-resistant varieties were introduced, they cross-pollinated and produced viable fruits – lots of them. Unfortunately, Callery Pear sprouts readily when cut, and is hard to kill with herbicides. Consequently, it’s crowding out native vegetation. 

Invasive Callery Pears. Photo by Mort Schmidt. 

Callery Pear has no commercial value aside from landscaping. The trees are too small for commercial lumber, and the wood has a tendency to crack in drying. However amatuer woodworkers report that small pieces are good for turning and carving, because of the wood’s uniform grain, smooth texture, and uniform color. All agree that it burns hot and clean, and leaves little ash. If nothing else, Callery Pear serves to remind us that the best intentions can go awry, especially when introducing exotic plants and animals. 

Comments are closed.