Callery pear is a small to medium-sized tree with a compact, symmetrical, pyramidal or columnar shape that spreads to become oval with age. Many cultivars exist with slightly different characteristics; all contribute to the species' invasiveness.
Leaves are alternate, simple, generally oval, to 3 inches long, with rounded teeth, glossy green, turning orange, gold, red, pink, and/or purple in fall. Some cultivars develop patterns of colored circles and spots in autumn. Leaves bob in the wind on long leaf stems.
Bark is gray-brown, smooth on young trees, splitting into scales with age.
Twigs are thornless in cultivated trees, but in wild types (including trees that develop from sprouts of a tree that was felled), the twigs end in thorns.
Flowers in early spring; abundant clusters of white flowers, 5-petaled, each to ¾ inch wide, unpleasant-smelling.
Fruits like tiny, hard apples, round, to ½ inch in diameter, greenish-yellow flecked with whitish spots, inedible, with 2–4 black seeds. After freezes they soften, darken, wrinkle, and become palatable to birds.
Similar species: Several other trees bloom in spring with white, five-petaled flowers. Serviceberry has petals that are brighter white, strap-shaped, wavy, with a space between them (not rounded and close together). Native plums have stamens (threadlike stalks in the center of the flower) that are longer than the petals. Apple and crabapple flowers have a slightly pink hue, and apple tree branches are nearer to horizontal and less uniform, compared to the vertical, symmetrical branching of Callery pear.
Height: 30–50 feet ('Bradford' variety).
Habitat and Conservation
Sometimes a certain variety or cultivar of a tree becomes so popular that the whole species becomes known by that name. 'Bradford' pear is a variety of Callery pear, and it has been hugely popular in landscaping. Its adaptability to a wide variety of growing conditions contributed to its popularity. You can find it in urban, suburban, and rural yards, office and apartment complexes, malls, streets, and college campuses. It grows quickly but dies young, frequently breaking in strong winds. Its vigor and adaptability have contributed to its invasiveness. We recommend planting a variety of other small trees, especially natives such as serviceberry, yellowwood, redbud, and hornbeam.
Invasive. Native to China and Taiwan, Callery pear has been a hot landscaping plant for decades. The 'Bradford' cultivar is created when a scion (cutting) of a 'Bradford' tree is grafted onto the rootstock of a wild-type Callery pear. The cultivated forms were thought to be sterile, but recently they’ve been spreading — alarmingly. This happens when many different forms are planted close by (as in towns), then can cross-pollinate and produce viable fruits. Also, when it gets large, Callery pear develops "weak crotches" where the limbs join the trunk, and the tree is easily split or knocked over by wind. After the fallen tree is removed, sprouts appear at the stump and will grow into the wild, thorny, invasive form of the tree, whose fertile fruits are spread by birds and other animals.
If you are considering planting an ornamental pear, do your homework: 'Bradford' tends to produce heavy limbs with narrow branch unions that may fail under an ice or wind load. But other cultivars have been developed that are studier and less invasive. Even better, plant native trees! Learn before you plant! The name Callery honors the nineteenth-century French priest and Sinologist (scholar of China), Joseph-Marie Callery, who sent samples of this plant to botanists in Europe. Callery pear was imported to America by Frank Meyer, a USDA scientist working in China tasked with locating disease-resistant fruit trees for US agriculture. (The sweet-tasting Meyer lemon was named for him.) The cultivar 'Bradford' was named for Frederick Charles Bradford, one of the chiefs at a USDA plant station in Maryland in the early 1950s, who noticed the tree's ornamental qualities and began work to develop the cultivar named for him. 'Bradford' pear was released to the public in 1963, 12 years after Bradford's death.
When they become invasive, Callery pears can crowd and shade out our native plants, reducing the diversity of plants and, thus, of animals too. The wild forms often develop characteristics of the original Chinese trees, including stout thorns that make them difficult to clear.