Most likely your tree has a disease called peach leaf curl. The leaves should be puckered with a pinkish tinge. What usually happens is that the infected leaves drop off but the tree sends out more foliage that is okay. It is too late to do any type of control. Peach leaf curl is best controlled with a dormant spray of chlorothalonil (sold as Fertilome Broad Spectrum Landscape and Garden Fungicide, as well as other manufacturers). In the meantime, keep the tree healthy by watering during periods of drought and next year consider fertilizing the tree in spring to maintain vigor.
