Apple trees can be made to fit almost any size yard. This makes them an excellent tree choice, whether you have a large yard or only a small patio area for your tree. Apple trees are also very tolerant of a wide array of trimming styles. Your goal in trimming a young apple tree is to establish a strong framework for future growth, and your goal in pruning an established tree is to maintain the tree's pleasing shape as well as to encourage fruit growth.
Prune your apple tree in late winter or very early spring before new growth begins. Remove all dead and dying branches and any that appear diseased or broken. Use shears when possible, but whenever removing a branch that is 1 1/2 inches in diameter or greater, use the three-cut method. Start by sawing a cut from the underside of the branch approximately 3 inches farther out than you want your final cut. This underside cut should be no more than halfway through the branch. Next make a cut all the way through the branch from the top side, cutting approximately 3 inches farther along the branch than your underside cut. As this topside cut nears completion, the branch may break off at the point of the underside cut. (The underside cut will prevent the branch's bark from ripping off down the trunk of the tree). Now all that is left is to cut off the 6-inch stump of the branch just outside the branch node at the trunk.
Clip all suckers growing from the root area of the tree and then spread a liquid sucker stopper on the cuts you've made to prevent their regrowth. Sucker stoppers can be purchased at any nursery or home center. Follow the manufacturer's instructions. Do not apply sucker stopper if blooms or fruit have already set on the tree.
Cut any upward-growing branches that appear to be competing with the main trunk. You want your tree to have only one primary trunk.
Trim any branches that are growing downward.
Cut branches that are growing sideways through the canopy of the tree and branches that are crossing and rubbing against each other.
Cut the top of the main trunk off at approximately 32 to 36 inches if you have a young tree with no side branches. Cutting the top will encourage the growth of side branches. Do not cut off the top of the main trunk of an established tree.