Avoid Making These Common Mistakes When Pruning Your Fruit Trees

A healthy fruit tree is a magical thing. Besides providing a wealth of delicious food, a thriving tree creates shade and beauty and increases biodiversity in your yard. To keep fruit trees healthy and productive for many years to come, you'll need to prune them annually.  

Pruning is necessary for young and mature trees alike. It's one of the first things you should do after planting the sapling. As the tree continues growing, regular pruning remains a must if you want it to form a sturdy shape that supports plenty of fruit without bending or breaking. Pruning can also be helpful on a practical level for keeping the trees to a size you can easily handle in the garden. Once fruit trees mature, good pruning practices help them produce bountiful harvests and better-quality fruit. Cutting back branches properly stimulates growth from the buds that stay on the tree and increases the amount of light that makes it to the remaining branches.

However, pruning fruit trees improperly can have the opposite effect, making your trees weaker and less productive. Poor pruning practices can even invite harmful infections. To prune your trees the right way, avoid common mistakes, like bringing the shears out at the wrong time of year, making incorrect cuts, over-pruning, using wound dressings, and relying on the same methods for all your trees.

The worst time of year to prune is in the late spring or early summer. Pruning while a fruit tree is actively growing causes excess stress and makes it difficult to see what you're doing, which increases the possibility of making the wrong cuts or missing problems such as infected limbs. This is also when a tree is most likely to develop an infection after being cut. 

Pruning later in the summer can work for a healthy tree, but it still causes considerable stress (particularly if the conditions are dry). Try to only prune in the summer when it's necessary, like when a branch is dying or is about to break. You can also prune new shoots in the summer to allow more light to reach the fruit; this is particularly helpful for boosting the size and quality of peaches and nectarines. 

However, the best time of year to prune fruit trees is in the winter or early spring, when the trees are still dormant. Since cutting back when it's too cold is a mistake too, wait until the danger of frost has passed. Mature trees typically only need pruning once a year, and young trees should only be pruned as needed to create structure. Don't prune too often — it's hard on the trees, especially young ones, which need to preserve as much foliage as possible to grow healthy and establish roots.

It's important to remove only certain branches when you prune. The goal is to achieve a spread-out, up-swept shape, with each branch meeting the trunk at a 45- to 60-degree angle. Generally, don't remove branches unless they are dead, diseased, or growing in the wrong direction. To improve air circulation and sun exposure, remove branches that are growing toward the center of the tree, overlapping, sharing a fork with another close branch, or rubbing against each other. Cut off small vertical branches — known as "water sprouts" and "suckers" — near the area they connect to a larger branch. Don't remove all of them at once or they'll grow back.

"Heading" cuts don't shear off the entire branch, just the end of it. They help control the height of the tree, encourage branching, and help tree limbs grow strong and stiff rather than long and overly thin. During annual pruning, head back about 20% to 30% of the season's new growth on each branch. However, avoid heading back branches that are over a year old, as this can disfigure older trees, lead to disease, and cause more suckers or water sprouts to grow. Similarly, don't "top" the tree in an attempt to make it shorter; that's a common trimming practice that's actually killing your trees by encouraging infection. It also leads to the growth of more suckers. Instead, to reduce the overall height of the tree, remove branches that are higher than you prefer.

While "heading" cuts remove the end of a branch, "thinning" cuts get rid of the entire branch. In either case, cutting at the wrong spot can have negative consequences for the tree and increase the likelihood of an infection. So, avoid cutting too much or too little.

When thinning, always cut the branch off at the spot where it meets the trunk or another tree. Don't cut flush to that point, however. Instead, look for the branch's "collar," the raised area at the base, and cut just above it. Every cut that you make wounds the tree, and the branch collar contains cells that protect the tree from infection. If you cut below the collar, the tree will be much more vulnerable. That said, too long of a stub is also more difficult for the tree to heal.

When heading a branch, choosing where to cut entails measuring how much new growth to remove. But this is also an opportunity to keep the tree growing in the right direction. Choose a bud that's facing the direction you want the branch to grow in, outward from the center of the tree. Cut back to that bud. Again, cut just above the bud, not too close and not too far.

Making heading cuts at too narrow of an angle can lead to the branch breaking off later. Picturing the face of a clock, line your blade up with the 10 o'clock or 2 o'clock mark, which results in a nice, wide angle. It's also important to use sharpened tools to avoid making rough cuts, which can tear branches and leave additional, unnecessary wounds. Remember, every wound gives infection an opportunity to enter. When using the same tools on multiple trees, disinfect them with an isopropyl alcohol solution for 30 seconds after each tree.

Sticking to the best practices above means you won't have to dress the wounds. Indeed, wound dressing can also be considered a common mistake when pruning fruit trees — it used to be a popular method for preventing infection, but research has found it to be more harmful than helpful. It doesn't reduce the chance of wood rot, and the dressing itself can be home to organisms that cause disease.

Pruning requirements differ between fruit trees. For starters, certain shapes are more suitable for some trees than others. For example, the "central leader" shape has one main limb growing up the center from the trunk, with all the branches growing from this limb. This is an appropriate shape for apple, pear, sweet cherry, and European blue plum trees, among others. Meanwhile, the "open center" shape has one trunk that splits off into three to five scaffold limbs. It's appropriate for peach, apricot, nectarine, sour cherry, and Japanese plum trees. 

In addition, some pruning techniques only apply to certain species. For example, heading back branches can encourage fruit growth on pear and apple trees, but the approach won't work with cherries. Research your species before you prune.

Every tree is an individual, so it may not exactly fit the prescribed shape, but that's okay. Don't force it, and don't rush it either. It takes time to train a tree. Developing an open center shape takes four years, for example. Removing too much of the tree at once — more than one-third or so — is very stressful for the tree and can cause it to grow a ton of unproductive wood in response.