The art of pruning is important for the health and longevity of a fruit tree. Though a lot can be said about it, here I only want to give some basic tips that are easy to follow.
1. Keep in mind that by cutting of a branch, one creates a wound. This wound is a new entrance way for infectious diseases, which can cause a lot of harm to the tree. This means that it is important to make a good cut, in a way that the tree can protect itself for further damage. (Also modern science starts to understand now that plants and animals have many similar physiological working mechanisms, like protection against disease through circulation, antibodies…)
2. Cells which are capable of producing healing tissue are situated exactly at the junction of a branch to its parent limb. You want to save this tissue, so do not cut so short that you remove this tissue. But at the same time do not cut too far away from the junction otherwise the healing cells will not border the rim of the cut and will not be able to do anything and an open wound will always remain (see photo for the right distance).
3. The smaller the surface of the cut, the smaller the entry way for disease is and the smaller the surface is that the tree has to heal. Try to cut in the angle that results in the smallest surface possible.
4. Use sharp tools, so cuts will be straight and smooth. This makes healing easier.
5. When to prune? Different references will advise different moments for when to prune a tree. Most say that it should be done in the ‘dormant’ months, when no infective diseases are active, being November through March. Others advise that one should prune when the circulation of the tree is in full action, so defense mechanisms can protect and heal the created wound as fast as possible. Both theories carry parts of truth and wisdom, so it remains hard to point to the ultimate moment. I always keep following rule in mind: “better a good cut in the wrong season then a wrong cut in the right season.”