CRABAPPLES LOSING LEAVES?

A common ornamental tree disease arborist’s encounter in Michigan is apple scab. This foliar disease infects crabapple leaves in the spring, but does not make itself apparent until later in the summer. After the apple scab fungus has infected enough of the crabapple leaf the leaf will fall from the tree.

Crabapple trees infected with apple scab usually start to show the effects of the disease between mid-June and early July. By August some crabapple trees may have even lost most of their leaves.

If your crabapple tree has lost a lot of its leaves from apple scab it is really not worth spraying the tree with a fungicide at this time. The disease is already in the leaf tissue and further apple scab infection is not going to be significant in the warmer and drier months of the year. Make sure the tree is receiving ample water and you may want to consider fertilizing in the fall to assure adequate nutrients are available to the tree.

The best way to prevent apple scab in the future is to apply a foliar fungicide spray in the early spring. Crabapple spraying for apple scab should start soon after the leaves begin to emerge. A couple follow up treatments will give you the best level of control.

To learn more about controlling apple scab click here:
http://www.owentree.com/Apple_Scab.php

Apple scab infection