Apple trees are among the most widely adapted and rewarding fruit trees you can grow. There are literally hundreds of varieties, with one or more suited to almost every climate. To remain healthy and productive, however, apple trees must be pruned (trimmed and shaped) each year. Apples bear their fruit on small spurs, which are compact shoots that form along larger branches. The spurs can remain productive for more than 10 years. Proper pruning keeps the spurs productive throughout the tree and replaces the unproductive limbs.
Don’t be anxious about pruning your apple tree. In most cases, any pruning is better than none. Follow the ‘how to’ guidelines outlined here, and your tree will remain healthy and productive. Even if you make a few mistakes, you’re unlikely to really damage the tree.
Training and Pruning
Apple trees, especially varieties grown on dwarf rootstock, are usually trained to a central leader, or main trunk. This method is called central-leader training. The leader is allowed to dominate, and the overall tree form looks something like a pyramid. (Peach trees, in contrast, are usually trained to a vase-shape, where the tree develops five or six main limbs and remains open in the center.) Do the major pruning in winter when trees are dormant. Prune in summer only to maintain size or remove diseased limbs.
The Benefits of Pruning an apple tree
It increases yield and improves the quality of the harvest. Pruning keeps the entire tree productive and gives you larger, better-looking fruit.
Pruning makes fruit easier to harvest. Pruning branches to keep the tree compact helps keep the fruit within easy reach.
Pruning helps control insects and diseases. Air circulates better within a well-pruned tree, which reduces the likelihood of disease. The tree is also easier to spray. Removing diseased or insect-damaged branches helps prevent infection and infestation from spreading.
Pruning strengthens the tree. Pruning helps the tree develop a strong framework that can handle the weight of its crop and endure the stresses caused by the elements.
Pruning creates a more attractive tree. A healthy, well-pruned tree simply looks better.
How to cut
Before you get started, it’s important to understand the basic pruning cuts and how plants respond to them. There are two types of pruning cuts: thinning cuts and heading cuts.
Thinning cuts remove entire branches or limbs, paring them back to their point of origin or the juncture where they meet another branch. Thinning opens the interior of the plant to receive more sunlight and channels energy into the remaining branches. In most cases, thinning enhances the natural shape of a plant. The thinning cut is the preferred type of cut for pruning apple trees.
Heading cuts are made anywhere along the length of a branch or limb to produce more vigorous growth below the cut. This growth is often weakly attached, however, with narrow angles that form between the original branch and the new growth. Heading cuts are necessary when pruning young trees, as explained below. Because mature trees seldom need lots of new branches, heading cuts are made less frequently as the tree ages.
The Right Tools
You’ll need the following tools to prune an apple tree:
- Bypass pruning shears (Amazon’s best choice), for hand-cutting small branches;
- Long-handled loppers (check on Amazon), to cut large branches;
- A pruning saw (here is one on Amazon that also folds) , to cut very large limbs;
- A sturdy ladder (little giant ladder at Amazon), if you’re pruning large trees;
- Gloves, to protect your hands.
- It also helps to have some type of sharpening stone so that you can keep your pruning shears sharp. Sharp tools are easier to use and do less damage to the tree.
Pruning cuts by year
Pruning a Young Tree. The goal with a young tree is to develop evenly spaced “scaffold” limbs that will grow off the main leader. The scaffolds will be the main branches of the tree. You select them at the beginning of the tree’s growth, then they support later growth (shoots that grow off the scaffolds). Correct scaffold selection and placement helps ensure that the tree’s crown isn’t too dense and that the center of the tree receives adequate sunlight. It also makes harvest easier. Another goal of pruning is to remove any limbs that compete with the central leader or with your selected scaffolds.
At planting. If you purchase an unbranched “whip,” you may have to head it back to encourage new branches to grow at the appropriate height (usually about 2 to 3 feet high). If you purchase a tree with its leader and first set of scaffolds already established, prune as described for the second year.
Second year. Near the end of the tree’s first dormant season, select two or three branches as scaffolds and head them back just above outward-facing buds. Select one shoot near the top of the trunk as the new leader (you may have to stake it to ensure that it grows straight up) and head it back about 2 or 3 feet above the lowest scaffold branch. Remove all other branches at the trunk.
Third year. Select a new set of scaffold branches about 2 feet above the first set, and remove other branches. Head back all scaffolds (and their side shoots) as before and head back the central leader about 1 to 2 feet above the second set of scaffold branches.
Fourth and subsequent years. Dwarf trees may be near mature height. New tiers of scaffolds can be established on larger trees.
To make sure limbs are strongly attached and to encourage early spur formation, it’s a good idea to spread recently selected scaffold limbs so that they form about a 45-degree angle at their base. To spread them, place a clothespin or a short piece of wood that has been notched at both ends between the scaffold limb and the main trunk. You can also hang weights from the limb to spread the angle.
The tree will produce some fruit within a few years of its initial pruning. Don’t be concerned about yields yet: this is the time to establish well-spaced healthy scaffolds.
As apple trees mature, your goal is to let light and air into the center of the tree by removing crowded, crisscrossing and dead branches. Also prune to maintain productivity throughout the canopy by removing branches that have become unproductive and making heading cuts on selected branches to produce new, productive growth.
Remove diseased or damaged limbs and limbs that compete with the central leader. Suckers are the small shoots that grow from below the bud union, a swollen area at the base of the tree. (Desirable apple varieties are usually grafted onto selected rootstock to produce a durable, hardy tree. The bud union is where the two are joined.) Cut suckers off as flush to the trunk as possible.
Apple trees are prolific; they often set a more robust crop of fruit than the limbs can support. Thinning fruit is a good idea; it promotes good fruit size and blooms for the following year. Plus, it will prevent tree breakage. Generally, every apple blossom results in a bloom cluster of 5 or 6 blossoms. Apples should be thinned when they are about the size of a marble. Try to leave the remaining apples 4 to 6 inches apart, and clip off enough fruit to leave only one fruit per cluster. You may feel a bit too aggressive with your pruning, but don’t limit your efforts—you’ll harvest higher-quality fruit, reduce insect and disease problems, and increase chances for a full crop next year.
Because apple trees bear on short, long-lived spurs, they’re particularly adaptable to being grown and pruned as formal espaliers, where they’re trained in a flat plane, usually against a wall or trellis. Formal espaliers have their main limbs (called cordons) trained in recognizable patterns—for example, horizontal, angled or even arched arms. Growing apples as espaliers takes judicious pruning and tying, but it results in unique garden art. This technique also allows you to grow apples in a very small space.
Because they allow for increased air circulation and exposure to sunlight, espaliers are, if anything, less susceptible to problems than tree forms, unless they’re exposed to too much heat or humidity. Although neither of these problems is likely to be very serious, they can hamper an espaliered apple tree’s health and productivity.
South-facing walls in hot climates act as heat sinks and might cause damage to a tree espalier against them. Where conditions are humid, air circulation next to the wall will be somewhat restricted and pose humidity-related problems. In areas with very hot summers or humid conditions, it’s probably best to grow espaliers on wires in the open air, rather than against a wall.