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Leaf and tar spots can be a problem during wet weather. The spots appear as small brown or black spots on the top of leaves often developing in early to mid summer. Since the disease is rarely serious, no chemical controls are normally needed. However, in severe cases or to improve the look of the tree, spray the tree with Liquid Copper Fungicide. The fungicide spray should be applied when the leaf spots are first noticed and again in about 14 to 20 days. The following spring, shortly after bud break, re-spray the tree to ensure no over-wintering of the spot disease. Since the leaf spot fungus over winters in the fallen leaves and then re-infects the tree the following spring, it is important in the autumn to collect up and remove any leaves that have fallen to the ground.