Pruning a young or mature apple tree can seem daunting especially if you spend any time reading the countless books on the subject. As with all garden tasks, there are lots of nuances to fruit tree pruning that can be learned and mastered in time as you become a more confident gardener. However, with an understanding of the basic principles, you will be on your way to attaining a beautiful and productive tree.
For starters, apple trees are pruned during winter dormancy when saps levels are low and you can clearly see the branching structure. For most regions, this will be in the months of January, February or early March at the latest. When you are ready, gather the correct tools including a sharp pair of loppers, hand pruners and a good tree saw. Safety glasses, gloves, and an orchard ladder will also come in handy.
As with any pruning, always have a goal in mind before you make a cut. Ask yourself the question: “What am I trying to achieve with this cut?” Also ask yourself: “What kind of cut will I use to achieve my goal: a heading cut or a thinning cut?” Heading cuts are made by removing the terminal portion (or tip) of a shoot or limb while thinning cuts involve the removal of an entire shoot or limb back to its point of origin on the branch it arose from.
For young apple trees that are less than 4 years old, the aim is to establish strong scaffold branches. Scaffold branches are the main structural branches of the tree that will form the “look” of the tree as it matures. Fruit-bearing secondary branches will then grow from the scaffold branches. To achieve good scaffold branches, select several branches 8 to 9 inches apart and evenly spaced up the trunk. Remove all the other branches and allow the remaining ones to grow. For the next 2-3 years, continue to select scaffold branches as the tree grows in size.
Trees that are older than 4 years are considered mature. The general goal of pruning a mature apple tree is to create an open structure that allows plenty of light and air circulation in its center. This helps decrease disease while encouraging flowering and fruit set. Imagine the open structure looking like your cupped hand with your fingers representing the branches around your palm. On these branches will grow a number of “spurs.” Spurs are very short branches (up to an inch or so) that grow on second-year wood. Their buds produce flowers that once pollinated will become fruit. It is very important before you begin to prune a mature apple tree to identify branches with spurs that you will leave so that you don’t compromise your fruit production.
Depending on the age of your apple tree and how much pruning it has received in the past, start by looking for and pruning the following items:
1. Suckers growing below the graft- These will be near ground level and arise from the root stock. Root stocks are chosen for various reasons including size control, disease, and soil adaption but are usually undesirable for fruit production. If graft suckers are allowed to grow, they can come to dominate the tree making it less productive.
2. Water sprouts- These are the straight growing leafy shoots that grew last year up though the canopy. Water sprouts tend not to produce fruit and should be removed annually.
3. Stubs or broken branches
4. Downward-growing branches- These are usually best pruned with heading cuts to help lift the canopy and prevent breakage from the weight of the ripening fruit.
5. Rubbing or crossing branches
6. Shaded interior branches- These are usually secondary branches and are often removed with thinning cuts.
7. Competing leaders- These are two branches growing alongside each other competing to form the canopy of the tree. It is best to choose one to become the leader and subordinate the other with a heading cut.
8. Narrow crotches- These occur when two branches arise too closely to each other often creating a weak attachment that is prone to breakage.
Once you have finished with these items, now look at the tree’s secondary branches and evaluate them for additional pruning. Depending on the size and age of your tree, more secondary branches can be pruned in order to reduce the size of the tree, to further create an open structure and for general shape so that the tree is still attractive once you are finished. Pruning older secondary branches also directs energy into younger more productive branches.
As you prune, remember to take frequent breaks to stand back and review what you have accomplished as you don’t want to get too overzealous and remove more than a third of the canopy. This can stress your tree and cause excessive non-productive growth. If you are unsure about removing a branch or making a cut, then leave it for another year and observe how it grows next season.