With dainty blossoms in early spring; great shade foliage; and sweet, crunchy fruit, apple trees (Malus spp.) are valued additions to the home garden during growing season. To get top results, gardeners must understand and pay careful attention to cultural tree care, including sun and water requirements and pruning.
Pruning apple trees is an essential part of maintenance for these fruit trees, and depending on what you read, the task may feel overwhelming. But it doesn't have to be overwhelming as long as you understand the basic principles of pruning and adapt them to each tree. Keep in mind that almost every expert offers different advice for how to prune apple trees, so there is no perfect method. But failure to prune at all can result in low fruit production, and it can even kill the tree.
Start assimilating information about when and how to prune apple trees by learning the basic principles of pruning fruit trees.
When to Prune Apple Trees
The purpose of pruning apple trees is to give the trees a strong branch structure and to stimulate vigorous growth from the remaining buds. An apple tree must first be pruned at the time of transplant, which usually happens in spring or fall. But for annual maintenance or for removal of large limbs, the best time to prune an apple tree is during the late winter dormant season between February and April. Avoid making pruning cuts to fruit trees in early winter since this can increase the risk of severe winter injury to the trees.
As you notice it, do a light pruning to remove:
- diseased branches
- damaged branches
- dead branches
- dead wood
The Two Types of Apple Trees
In order to prune your apple tree correctly, you must understand that there are two different types: some apple trees are spur bearing, and others are tip bearing. These two different types of apple trees must be pruned slightly differently to maximize fruit production. Spur-bearing apple trees are naturally less vigorous than the others and should not go through heavy pruning. An uninformed grower can prevent a tree from producing apples with improper pruning. If you are not sure, look at the branches closely.
Spurs are modified shoots under 6 inches long with a compressed growth structure produced after a branch is 2 years old. Each year, fruiting spurs add a small amount of new growth that looks like wrinkled rings around the spur. Spurs sprout laterally from the sides of branches all along the length. Spur-bearing fruit trees are shorter trees with shorter branches yet have more fruit buds than tip-bearing trees do. They develop many small spurs rather than long shoots, so fewer should be removed. Many strains of the popular Delicious and Macintosh apples are spur-type apple cultivars.
The second type of apple tree is nonspur, or tip bearing. The tree has a weeping shape with downward-growing branches and sets fruit on the tip of longer shoots. Tip-bearing varieties include many strains of Rome Beauty and Granny Smith.
Pruning Apple Trees at Transplant
Apple trees must be pruned at the time of transplant. This is usually done by the growers, but if not, the gardener must start to train from the day of planting. Neglecting the pruning of fruit trees results in poor growth and delayed fruiting.
A new apple tree must be trained to a central leader system and should form a pyramidal shape. That means that the tree must be pruned to have one main trunk in the center of the tree and a structure of scaffold branches or side branches.
If the tree is a whip, which is an unbranched tree:
- Cut it back to between 28 and 35 inches using pruning tools.
- When the buds grow out to 4 to 5 inches, select a central leader and up to six scaffold branches with wide crotch angles. Scaffolds are side branches that should be at least 6 inches apart vertically and spaced at equal intervals around the trunk.
- All other lateral branches should be taken out.
If you purchase young trees that have been branched by the grower:
- Prune out any broken branches and those that form narrow crotch angles.
- The first year, remove upright center branches except for the central leader at the top of the tree.
- The second year, trim the leader by one-third, making a heading cut close to a lateral branch or bud that is growing in a good direction.
Having trouble visualizing the process? Check out this video from eHow:
Pruning Apple Trees in Winter
When it comes to annual apple pruning, rather than trying to follow precise rules, the key is to understand basic pruning principles and apply them to bearing apple trees. Prune lightly to moderately since excessive pruning is bad for the tree; it overstimulates the growth of water sprouts and delays fruit maturity.
- Remove all broken, dead, or diseased branches using pruners; loppers; or for large branches, a pruning saw. This can be done in winter, but it can also be done at any point to prevent disease and/or insect issues. This is also true for fast-growing suckers and water sprouts.
- Look for crossing branches and remove the weaker one. Make a thinning cut just outside the outer edge of the branch collar to minimize healing time.
- Do not try to change the natural growth habit of the tree.
The rule of thumb is to prune upper branches more than lower branches to allow in sunlight.
- Eliminate branches that make narrow crotch angles to prevent splitting or breaking under crop load stress. Narrow-angled crotches are weak and can split if they become heavy with fruit or ice.
In addition, prune out new branches that head sharply up or down.
- If trees are too tall for easy maintenance, prune back the main upright branches with a heading cut to a
well-developed horizontal lateral. The central leader should remain the tallest shoot.
- For overgrown apple trees, the main objective is to open up the
interior of the tree to allow good light penetration.
How to Thin Apple Fruit
Thinning apples yields to better fruit — helping to increase fruit size, color, and quality. It also prevents limb breakage and stimulates flowering for next year’s crop. It is possible to thin apple trees in the backyard orchard by hand. During May and June, apple trees will drop small fruit on their own, a natural process that is necessary for the tree to mature the remaining crop. Act within 20 to 40 days of full bloom. Thin the apples, leaving fruit spaced 6 to 8 inches apart on the branch, favoring the center bloom in the cluster of five flowers since it will be the largest fruit.