Fire Blight of Ornamentals

Dr. John F. Baniecki
WVU Extension Service
Plant Pathology and
Entomology Specialist
August 2000

Although fire blight is considered to be primarily a disease of apple and pear, it is also a problem of many ornamental trees and shrubs of the Rosaceae family.

The symptoms of this disease are the sudden wilting of the leaves and flowers near the growing tips. These wilted leaves and flowers turn brown and then become black giving the appearance of fire scorching. The infection may spread down into the twigs and may even involve large branches. Some of the larger ornamental trees develop extensive cankers on the main limbs as well as on the trunk. Some of the flowering ornamentals, such as the flowering quince, are susceptible only in the blossoms. This type of infection gives an appearance of frost injury and may be mistakenly diagnosed as such.

The causal bacterium (Erwinia amylovora) is spread from diseased plants to healthy ones by insects and splashing rains. Infection occurs through unprotected wounds and through natural openings in the blossoms.