In much of North America, cultivars of P. calleryana are so widely planted as ornamental trees that they have become an ubiquity in many urban and suburban communities. It is tolerant of a variety of soil types, drainage levels, and soil acidity. Its crown shape varies from ovate to elliptical. The symmetry of several cultivars lends to their use in somewhat formal settings, such as city streets, shopping centers, office parks, and industrial parks. Its dense clusters of white blossoms are conspicuous in early spring along the boulevards of many eastern United States towns. At the latitude of Pittsburgh, Pennsylvania, the trees often remain green until mid-November, and in warm autumns, the colors are often a brilliant end to the fall color season, although in a cold year they may get frozen off before coloring. In the South, Callery pears tend to be among the more reliable coloring trees.
Several cultivars of Callery pear are offered commercially, including 'Aristocrat', 'Autumn Blaze', 'Bradford' (the commonly planted Bradford pear), 'Capital', 'Chanticleer' (also known as 'Cleveland Select'), 'New Bradford', 'Redspire', and 'Whitehouse'.
The neat, dense upward growth of 'Bradford' which made it desirable in cramped urban spaces — also results in a multitude of narrow, weak forks, unless corrected by selective pruning at an early stage. These weak crotches make the Bradford Pear very susceptible to storm damage where snowfall is heavy or when ice storms occur, or during the high winds of severe thunderstorms. Because of this, and the resulting relatively short life span (typically less than 25 years), many groups have discouraged further planting of 'Bradford' itself in favor of other, stronger Callery pear cultivars (such other as 'Cleveland Select'), as well as increased use of locally native ornamental tree species.
Тип: scenery