Pruning Apple Trees

Survival

When your apple tree is dug up from our fields to be shipped to you, and any time a tree is transplanted, the root ball loses many of its fine feeder roots. These hairlike, delicate roots are important to the process of absorbing moisture and nutrients in the soil. Pruning, in this instance, helps balance the top growth of your tree with the root system, giving the roots time to re-establish in your yard to support existing top growth and new growth.

When your bare-root apple tree arrives from Stark Bro’s, our professionals have already pre-pruned your tree for you. Because of this, you do not need to prune them again at planting time. The only pruning necessary at planting time would be to remove any broken or damaged branches and roots.

Plan to prune your apple trees every year during their dormant season. In Zone 6 and north, you should wait until late winter. A good reference book, such as Pruning Made Easy, can be invaluable for providing additional visuals and answering questions you may have during the pruning process.

Stimulation

In addition to the survival benefits, pruning an apple tree stimulates stronger, more vigorous growth from the remaining buds. After a single growing season, an apple tree you prune will be bigger with stronger branching than a matching, unpruned apple tree.

Shape and Structure

Equally as important to the benefits above, your apple tree needs to be pruned to provide a strongly structured shape. The natural shape an apple tree takes on is not always the best for its maximum fruit production. Stark Bro’s apple trees are pruned in the nursery row for proper shaping to get you started and corrective pruning must continue at home. If you keep up with your pruning and shaping each year, it will be a reasonable task mostly involving small, easy-to-heal cuts.

Pruning Tips

Pruning angles

Narrow, V-shape crotch angles in the limbs are an open invitation to disastrous splitting later on, particularly when your apple tree is supporting a large fruit crop. For your tree’s branches, choose wide 10 o’clock and 2 o’clock angles.

Pruning to a bud

Make sharp, clean cuts close enough (about 1/4 inch away from the next outward-pointing bud) so you won’t leave a clumsy stub that’s hard to heal over. Stay far enough above the bud so it won’t die back. Slant the cuts and the new growth will develop beautifully.

Every branch has buds pointed in various directions. Since you want vigorous new growth to spread out and away from the center of the tree, make you cut above a bud that’s aimed outward. These are usually located on the underside of the branch. This helps your apple tree take on a more spreading shape, keeping it open to light and air circulation.

Prune for Success

Apple trees develop better if they’re pruned in a timely manner and with a bit of care and consideration. Here’s how:

Help the tree form a strong framework. This is what you should aim for when pruning:

• Remove weak, diseased, injured, or narrow-angle branches.
• Remove the weaker of any crossing or interfering branches, and one branch of forked limbs.
• Remove upright branches and any that sweep back inward toward the center of tree.

The purpose is to keep your apple tree’s canopy from becoming too thick and crowded, so some thinning is necessary to permit light to enter the tree and also to keep its height reasonable. All these objectives promote the improved bearing and fruit quality of your apple tree – you’ll be pleased with the results!

Prune apple trees to a “Central Leader” shape.

Apple trees are productive and strong when pruned and trained to a central leader (or main leader) structure. This type of structure has a pyramidal shape with a single upright leader limb as its highest point. This central leader is the newest extension of a long, upright growing trunk from which all lateral branches arise.

As with all strong-growing branches, the leader should be headed (pruned back) at approximately 24- to 30-inches above the highest set of its surrounding “scaffold” branches. The uppermost remaining bud on the leader will then produce a vigorous new leader, and no other shoot should be allowed to grow taller.

Lateral limbs should be selected from shoots growing out from the central leader. These should be spaced vertically about 4- to 6-inches apart. They should also have growth that is more horizontal than vertical, and point in different compass directions from the trunk – thus creating a “scaffold” of branches. Any unbranched lateral branches should be headed back to the next ideal bud to encourage side branches and to stiffen long, lateral branches. All laterals should exhibit the stronger wide angles discussed above.

Pruning Whips (Unbranched Trees)

Whips are unbranched trees. Unbranched apple trees are ideal if you want more control over which branches are allowed to develop – as you might in certain artful pruning styles like espalier. Prune whips back to 28- to 36-inches above the ground at planting time. After the new branches have grown 3- to 5-inches in length, select a shoot to become the leader and the rest become the tree’s scaffold limbs.

Off-season pruning

Sometimes pruning needs to be done even when the season isn’t ideal. If a branch is broken by the wind or by a heavy load of fruit, emergency treatment is necessary. When taking action due to injury, prune to clean up any ragged edges; making a smooth cut that leaves no stubby stump.

It does not benefit the apple tree to wait until dormancy to prune damaged, dead, or diseased limbs or to remove unwanted growth like suckers and watersprouts. Fast-growing tree suckers and watersprouts should be completely removed as soon as you see them.

Spur pruning

You should not prune a spur-type apple tree as aggressively as you would a partial-tip or tip-bearing apple tree. Spur-bearing apple trees are naturally less vigorous than the others and do not require it. In apple trees with a spur-bearing habit, fruit develops on each limb and from the trunk out. They develop many small spurs rather than long shoots, so fewer should be removed. On the other hand, sometimes too many fruit spurs grow along a branch and may need to be thinned out to encourage bigger and better fruit on what remains.

Fruit Thinning

There are several reasons to thin fruit:

• To reduce limb breakage
• Increase fruit size
• Improve fruit color and quality
• Stimulate floral initiation for next year’s crop

Home gardeners are able to effectively thin apple trees by hand. During May and June in most areas, many apple trees will start to drop or abort underripe fruit. This is a natural process that allows the tree to mature the remaining crop load. If not corrected through thinning, apple trees may bear biennially (fruits only every other year) or bear heavily one year, then bear a comparatively light crop the next year. Thinning may seem counterproductive in theory, but it really is a benefit to your apple harvest in the end.

The best time to thin apple trees is within 20 to 40 days of full bloom. Thin so that each remaining apple is spaced 6 to 8 inches apart on the branch. In clusters, leave the king bloom (the center bloom in the cluster of five flowers) as it will develop into the largest fruit. On spur-type apple varieties, many fruit spurs grow along a branch and will need to be thinned out to encourage bigger and better fruit on what remains.