The Bradford pear tree enjoys popularity as an attractive ornamental tree. However, this Bradford pear is a delicate beauty. During the cold Colorado winters, its weak branches often break. After suffering from the stress of cold weather and broken or breaking branches, the Bradford pear tree becomes quite susceptible to disease.
In Colorado, Bradford pear trees often experience leaf scorch when grown in soil with high salt content. However, leaf scorch can also strike during an unseasonably hot and dry Colorado summer. Healthy adult Bradford pears rarely suffer from leaf scorch, but weak, injured or newly planted trees are quite susceptible. The leaves of trees suffering from leaf scorch are brown and dry on their edges, and severe cases may brown the whole leaf and cause it to drop. This "scorched" appearance is due to the tree's inability to provide its leaves with enough water. This condition is not deadly and will go away once the weather returns to normal or the salt is leached from the soil.
Fire blight besieges Bradford pear trees in early spring when new growth is developing. The bacteria responsible for fire blight causes the tree's leaves, buds and fruit to turn black and then drop. As the bacteria spreads, it moves into the wood of the tree which may ooze a sticky milk-colored liquid during rain. Fire blight is a deadly Bradford pear disease for which there is no cure. Affected Bradford pears should be uprooted immediately to stop the spread of infection and replaced with a fire blight-resistant cultivar.
Leaf Spot Disease
Leaf spot often crops up after a period of heavy rain in the spring or the fall. Once infected, Bradford pear leaves will develop purplish-red spots that often have a red ring around them. As the fungus spreads, the spots grow larger and cover most of the leaf. Those areas of purple-red then turn black and may drop out of the leaf, leaving a gaping hole behind. Spot disease in fall or spring during or shortly after exceptionally rainy weather. If left untreated, infected leaves will eventually drop. Eliminate leaf spot with the application of a fungicide prescribed for the disease.