When pruning an apple tree, a little effort goes a long way. By nature, apple trees are inclined to produce copious amounts of leafy growth and few fruits. Yearly pruning to thin out the canopy and make way for more fruit will flip the script and yield a generous harvest. Just 30 minutes of pruning directs the growth of a dwarf apple tree for another year of good fruit production. Researchers have found that regular pruning results in a larger bounty of fruit and sweeter, more flavor-rich apples as sunlight reaches into the canopy, fully ripening the fruit. Knowing how and when to prune apple trees is the key to getting your sweetest harvest yet.

Make It an Annual Affair

As far as when to prune apple trees, you'll want to do so every year. Yearly pruning promotes yearly fruit production. Removing large quantities of branches (one-third or more of the overall tree) will cause a tree to produce lots of leafy growth and no fruit. The leafy growth is the tree’s response to stress—it's attempting to regain its energy-producing structures to sustain itself. Avoid the stress response and lack of fruiting altogether by making small pruning cuts each year rather than heavy pruning every few years.

Watch the Calendar

To get season-specific on when to prune apple trees, late winter or early spring is the best time for pruning. Aim to prune trees when the coldest weather has passed but before the trees start growing in spring. Wounds will heal quickly in spring and the bare branches make it easier to see the tree’s structure. Don’t prune during fall or early winter. A cold winter can cause severe damage to recently pruned areas. 

Look for Diseased, Dead, or Crossing Branches

Knowing when to prune apple trees is a good start, but knowing how to prune them is just as important. Begin pruning a tree by culling troublesome branches that are clearly diseased, dead, or crossing. Diseased branches are identified by growths or sunken areas in the bark. A diseased branch may also be discolored. Dead branches are brittle and break easily when bent. Crossing branches are those that rub on a nearby stem or grow into the path of a desirable stem.

Mind the Leader

Most apple trees have a central leader or stem that grows toward the sky. Branches extend from the central leader in whorls to give the tree a pyramid shape. The central leader provides the main structure or center framework for the tree. Avoid pruning it severely. It can be pruned back by a foot or two to keep the tree small and manageable, but it should not be pruned severely or removed.

Let the Light In

Sunlight is an essential ingredient in apple formation. Your yard's sunlight must penetrate the tree canopy, reaching buds and then developing fruit to spur the fruit to maturity. Too many leafy branches halt the sunlight and stop apple development. An important goal in pruning fruit trees is to remove excessive leafy growth in the inner portion of the tree. 

Begin by pruning vigorous upright shoots. These are likely water sprouts and do not produce fruit. Next, prune closely-spaced branches, leaving branches growing away from the trunk that are well-spaced to nearby branches. Finally, trim any branches or side shoots growing toward the tree's center. 

Step Back

Step away from the tree frequently throughout the pruning process. A distant perspective will help you see the overall framework of the tree and what needs to be pruned next. Look at the overall shape of the tree. It should have a loose pyramidal shape. Identify the central leader. Analyze branch spacing, identifying branches that are growing too close together. 

Plan for 3 Years

Bringing an old, overgrown apple tree back into shape is at least a 3-year process. Begin by identifying the main structure of the tree. Identify the leader and the well-placed branches extending out from it. In the first year, remove select branches to expose the inner branches to light and air movement. Be careful to remove no more than one-third of the tree’s overall wood. The next year, continue removing excess growth and opening the center to light. In year three, remove the last of the excess large limbs and trim back long limbs to give the tree a pyramidal shape. 

Be Mindful of Angles

The angle at which a branch extends from the main trunk (or central leader) often determines its strength. A branch extending at a narrow angle of 45 degrees or less is prone to weakness and breakage. The strongest branches extend from the trunk at about a 60-degree angle. When pruning, look for narrow branch angles and eliminate them when possible. Encourage a wider angle on young branches by wedging a notched stick between the branch and the trunk at the beginning of the season. Remove the spreader stick at the end of the growing season. 

Topping vs. Crown Reduction

Topping is a pruning technique for reducing the height of a tree, but it's one that arborists typically don't recommend. Topping a tree involves indiscriminately making cuts to the top growth of a tree, which can significantly weaken or kill the tree. The sole scenario in which tree topping is okay is if a tree has suffered severe damage from a storm or natural disaster.

Crown reduction is the preferred method for controlling a tree's size. Branches from the crown of a tree are selectively removed to reduce height and increase airflow through the canopy, which leaves the structure of the crown unharmed.