By Ken Johnson
Callery pear (Pyrus calleryana) has been blooming throughout the area. It has been a popular tree to plant, especially in residential areas, over the years. Trees will reach 30 to 40 feet in height and produce large amounts of white flowers in the spring. Trees also have attractive glossy leaves that will turn a brilliant red-orange in the fall.
Callery pear has been imported to the U.S. multiple times. It was originally imported from Asia in 1909 to the Arnold Arboretum Harvard University and again in 1916 by the U.S. Department of Agriculture for development of fire blight resistance in the common pear (Pyrus communis), which was devastating the commercial pear industry at that time. It was used widely as a rootstock for pears before gaining interest as an ornamental plant. In the 1950s the ornamental value and hardiness of callery pears was recognized, which led to the development of a number of cultivars, including the most well-known ‘Bradford’. By the 1980s, ‘Bradford’ pears had become the second most popular tree in the U.S.
It has been widely planted due to its quick growth, adaptability to a wide range of soils, and pollution and drought tolerance. The trees also have a symmetrical-to-round shape that many people find desirable in addition to their abundant spring floral display.
Unfortunately, callery pear has several negatives to it. They have narrow branch angles and this, along with their rapid growth, makes them rather weak. Trees often split and break apart during storms and often don’t last longer than 20 years before they begin to split apart. Also, while the floral display may be impressive, the smell is not.
When ‘Bradford’ pears were originally introduced to the landscape trade, they were touted as having sterile fruit. This is because they are self-incompatible, meaning they require cross pollination from another cultivar. Since most of the callery pear trees that were originally planted were ‘Bradford’pears, there was very little pollination occurring (unless they were planted near another cultivar). However, once these original plantings began to reach the end of their short lifespan they were replaced by newer cultivars such as ‘Cleveland Select’, ‘Aristocrat,’ and ‘Redspire’. The introduction of these new cultivars meant greater chances for cross-pollination and therefore seed production.
This has led to the escape of callery pear into the environment. Birds and other wildlife will consume the fruits from trees and disperse them. Callery pear is now beginning to show up in disturbed as well as natural areas. As you drive along highway and interstates you can often see thickets of callery pears in fields along the roadside. Callery pears can quickly become established in an area due to their rapid growth as well as producing large amounts of seed. Once they become established, callery pears can form dense thickets that push out native species that cannot compete with them.
So, if you are considering planting a tree instead of planting callery pear consider alternative trees such as Dogwood (Cornus florida), Redbud (Cercis Canadensis), Serviceberry (Amelanchier spp.), and Hawthorn (Crataegus spp.). These trees have similar tree characteristics to callery pear, such as easy maintenance, small stature, and beautiful spring blossoms without the drawbacks of callery pear.