Pear trees were brought by early colonists to America’s eastern settlements. Most trees thrived until blight decimated orchards in the region. Pioneers brought pear trees to the Pacific Northwest in the 1800s, where they flourished and continue to do so today. Oregon and Washington boast not only the warm days and cool nights perfect for growth, but have the rich volcanic soil and ample moisture for trees and developing fruit. California is also a significant producer, with Michigan, New York, and Pennsylvania contributing to U.S. supply.
Types & Varieties
Three basic types of pears are grown in the United States: European or French pears, Oriental Hybrid, and Asian (often referred to as ‘apple-pears’ due to their crunchy texture).
Among the more popular European varieties are Bartlett, D’Anjou, Comice, and Bosc; a few Asian pear varieties are Chojuro, Ichiban Nashi (Nashi means pear in Japanese), Shinsui, Ya Li, and Yoinashi. It is unknown just how many pear varieties exist in the world, but it is believed to be in the thousands.
Fruit trees are not typically grown from seed but through propagation. Because pear trees do not root easily, they are grafting onto a rootstock.
Most cultivars require up to 1,200 chill hours (below 45°F) in winter to complete their dormant period. Fully dormant trees can survive temperatures as low as -25°F, pear blossoms, however, are extremely sensitive to frost and temperatures below 26°F.
Although trees tolerate multiple soil conditions, deep, well-drained soil is preferred, with plenty of water and humidity, though too much humidity can lead to blight and fungal growth.
Pests & Diseases
Pear psylla, similar to cicadas and aphids, attack all types of pear trees but are more dangerous for European than Asian varietals. Though very tiny, generally less than 3 millimeters in length, the insects can puncture and damage leaves, affect tree vigor, cause fruit drop, and honeydew secretions on fruit can lead to soot or mold. Worse yet, the insects are often able to develop resistance to insecticides.
Grape mealybugs are a pest of most deciduous fruit crops, including pear trees, where they may feed on calyxes, softening fruit. In older trees, the bugs are able to overwinter their eggs in coarse bark, becoming a problem in the spring. If found in harvested fruit, entire lots will be rejected as a preventive measure against further infestation.
Pear slugs are the larvae of sawflies, which deposit many small bubble-like eggs on the underside of leaves. Larvae feed on foliage causing skeletonization as the layers are chewed away.
Other pests of note include armyworms, cankerworms, cutworms, boxelder bugs, codling moths, leafrollers, mites, moths, lygus bugs, scale, stink bugs, and thrips.
Fire blight is the most serious of pear diseases, generally appearing in the spring and causing dark discolorations on blossoms, leaves, and twigs. In some cases, the entire tree dies. Pear scab begins as circular, brownish spots on leaves and stalks, turning into velvety patches. Fungus can overwinter in leafy groundcover and infected twigs.
Blue mold rot is a disease rarely found in the orchard; it occurs in storage and appears as soft, watery spots, generally due to mechanical injury, bruising, and cuts. Other diseases of concern include bacterial canker, black spot, blossom blast, crown and root rot, and pear decline.