What is it? Apple Scab is a fungal disease that can result in severe leaf and fruit spotting on apples and crabapples.
Why is this a problem? Infected trees will start to show brown spots on their leaves in mid to late Spring. If left untreated, the spotting on leaves and fruit will become more severe until the leaves turn yellow and drop off prematurely.
Recommended Treatment: A TruGreen program limits the damage caused by this disease. Complete control is extremely difficult, especially if not caught early enough. Keeping the plant pruned properly will increase air circulation and reduce humidity, which promotes apple scab. Also, rake crabapple leaves in the fall.