How to Manage Fire Blight in Apple and Pear Trees

Fire blight is a bacterial disease that affects apple and pear trees. Because of the contagious nature of this disease, it can be very destructive in an orchard setting. Once introduced, fire blight is nearly impossible to eliminate, which means it must be managed with regular pruning and treatment.

Fire Blight in Young Apple Branches

Fire blight can be identified by the damage it causes on new branches, leaves, and bark. New branch tips and leaves will be blackened and curled over as if scorched by fire. Fire blight will overwinter in cankers found in mature bark tissue. In the spring, these cankers will ooze and weep, and the sap from these cankers is filled with fire blight bacteria. Rain, irrigation, pruning, and other tree maintenance can easily spread fire blight to other parts of your tree and from one tree to another.

Fire Blight Cankers Ooze and Weep

The first step to managing fire blight is through pruning. All infected branches should be removed well below the infected area to ensure that the disease is eliminated from your tree. Fire blight should be removed immediately from your tree, no mater what time of year you identify the symptoms. Before pruning, and between each cut, make sure your tools are disinfected. Fire blight bacteria dies when exposed to extreme cold temperatures, so early winter pruning can help discourage the spread of the disease.

Disinfect Pruning Tools Between Cuts

Once introduced to an orchard, fire blight can be spread from one tree to another by bees and other pollinators in the spring. Trees that are infected with fire blight can be treated with copper after pruning. To avoid the spread of the disease from pollinators, you can spray your trees with copper as pedals fall in spring. If you use copper spray, make sure it is applied in the evening after pollinators have gone in for the night, so the spray can dry before morning. Also, copper sprays can burn leaves if applied in hot, sunny weather. Even though copper is considered an organic spray, make sure you are following the manufacturers label.

Bees Can Spread Fire Blight

With regular pruning and treatment, fire blight can be managed and prevented from killing your tree. Monitoring your trees regularly will help you to be proactive and prevent the spread from tree to tree.

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