Apple Tree is dropping leaves in early summer.

Asked June 29, 2018, 11:41 AM EDT

Hello, I am not sure what to do about my apple tree. I have lived in my home for 5 years. 2 years ago the apple tree in my backyard began to drop its leaves in the first 2 weeks of June. It never produced more that a few apples each year and most would fall off when they were about ping pong or golf ball size. 2 or 3 would become full apple size but the squirrels generally got to them. I don't care terribly about its fruit production but include the info in case it helps figure out why the tree is losing its leaves. This year will be the 3rd year the tree has followed the following pattern: In early spring the tree begins to leaf out as normal. Some flowers are produced. around the time the flowers are ending, leaves begin to develop discolorations. By the beginning of June, they begin to fall off while still a discolored green or they shrivel up while on the tree branch and then fall to the ground. This begins first on the lower leaves and then extends up to the canopy. New growth will appear but generally dries and shrivels before falling. I am attaching images of what the tree is like know. I am aware that it had Burr knots. Will that cause this issue? Is there anything I can do to keep the tree healthy and fix this problem? Thank you, Katie Hagen Perkins 262-366-9630

Frederick County Maryland

1 Response

The burr knots are not causing the problem. Based on the photos we think your tree is defoliating each year because of a fungal disease- apple scab (click "Diseases.") This is a polycyclic disease. The first spores to become active in spring infect new leaves. The fungus then reproduces itself by forming more spores that spread by wind and rain. This cycle repeats several times during the growing season. The disease will continue to weaken the tree and cause branch dieback.

To reduce the level and rate of injury; be diligent in raking up and disposing of any fallen leaves during the growing season and when leaves all fall off in October. You could also spray with a protectant fungicide early in spring. You would need to repeat the sprays and get excellent coverage of upper and lower leaf surfaces- not an easy thing to do with a large, old apple tree. jt