In mild years when most of the flowers survive, a tree may set more fruit than it is capable of supporting. The tree may then self-abort some of the fruit in a natural thinning process sometimes called "June drop." The tree will drop many small-sized (one-half to 1 inch in diameter) fruit at about the same time, making for a dramatic show. Horticulturists think competition for water and nutrients causes June drop. Peaches with the weakest seeds are usually the first to drop.

Most trees retain some fruit to carry through to maturity. It's unusual if your tree is truly dropping all of its fruit. Make sure you're providing adequate water and nutrients as the fruit matures. If all of what appears to be small fruits are falling off, it may be due to a lack of successful pollination. If there is frost damage to the pistil of the flower, the ovaries might begin to swell, and then drop off due to lack of development of the ovule into seed. Lack of bee activity could also bring the same result. If the fruit are staying on long enough to size up but are dropping before they ripen, it may be either a disease, such as scab, or some type of insect, such as stink bug or curculio. Since the possibilities are numerous, pay close attention this year, and see if you can narrow down the options.