What to do if your tree has Fire Blight

Crabapple trees are common sight in many landscapes. Their long-lasting blossoms are among the first to appear in spring, offering color to our gardens and forage for pollinators.

The crabapple and apple trees were beautiful this spring, flowering beyond expectations. But as the flowers began to fade and foliage developed, we began to see problems.

Sections of affected trees took on a gray-green appearance. Clusters of leaves turned brown with orange splotches.

Any remaining flowers or emerging fruit turned black and hung down limply.

These are all symptoms of a contagious disease called Fire blight. This disease affects mainly crabapple, apple and pear trees and it's been particularly bad this spring. The severity of the problem can be traced to spring rain, hail and wind, combined with the right temperature and an extraordinary bloom load on the trees. All of these factors contributed to this greater than normal outbreak of Fire blight.

If your trees are exhibiting these symptoms, you need to prune out the affected branches. Plan to make your pruning cut eight inches to twelve inches below the infected tips. It's important to know that you must sterilize your pruners between each cut. Otherwise, you risk moving the infection deeper into the tree. You can use a disinfectant such as Lysol or a ten-percent bleach solution. Bleach will rust your pruners so when you're done, clean your pruners in warm water with a Brillo pad, then apply a light coating of machine oil. Your other option is to wait until late winter and prune your tree while it's dormant. This approach will greatly reduce the risk of spreading the blight. 

Next spring, plan to spray your trees with Fire Blight spray. This should be done weekly through the bloom cycle. This fall, make sure you clean up any leaves and debris from under the tree.  There is no cure for Fire blight, but with good cultural practices such as pruning, timely spraying, clean up and deep root watering, you can mitigate the effects of this contagious disease to a certain extent.