Cut off all diseased, damaged and dead branches at any time of year. They are taking nutrients from other parts of the tree and are too weak to handle a fruit load.
Prune fruit trees that are sensitive to zone 7 frost in May. Cut off branches that are connected with narrow, V-shaped joints. Leave the stronger, U-shaped connections alone.
Remove water sprouts from apple trees in July. Target all upright shoots and the suckers that grow from the base of the fruit trees. They grow vigorously and use the water and nutrients that the rest of the tree needs to grow strong.
Head back branches that grow from the main trunk to the sides if they don't have branches growing off them. Prune a quarter of their length. This will encourage new branches to grow.
Unclog the air flow within the canopy of the fruit tree. Eliminate branches that cross or rub against each other because it's difficult for air to circulate among the leaves and fruit.
Avoid removing more than 30 percent of the fruit tree. Cutting off too much will cause poor fruit growth.