Paul Lynch is a permaculture designer and orchardist based in West Cork.
Apple tree pruning is considered by many to be a complicated job – which it can be – but there are some key concepts that, when properly understood, will direct what action should be taken (if any) and at what time of year. One of these concepts is the difference between summer and winter pruning.
In the winter the sap will have fallen and the tree stores its sugars in the roots. Pruning done then will not really rob the tree of its energy, and so increased vegetative or leafy growth can be expected during spring and summer after winter pruning, as a full tree’s worth of energy tries to express itself in the reduced tree size. Therefore winter pruning is more used to give structure and direction to younger growing trees and increase leafy growth in trees that are lacking vigour.
In the summer the sap is up in the branches and leaves, so pruning done now will rob the tree of some of its energy. This is very useful if the tree has too much leafy growth and too little fruiting wood, if a tree has outgrown its allocated area, or if it is desirable to limit its size or change its shape for any reason. It is an especially good time to remove the vertical leafy water shoots that can shade ripening fruit. Summer pruning is generally more important for mature trees.
Dead and diseased wood can be a little more obvious in the summer due to an absence of leaves, but removing this can be done in the winter also. The overall structure of a tree is easier to assess in the winter for the same reason.
Some general precautions to take are to use sharp tools and to disinfect them between trees and even between cuts on the same tree if there is any suspicion that you may have cut into diseased wood. As a rule only up to one third of the mass of a tree should be removed in any year, and only up to one sixth when summer pruning. Exceeding these limits can overly stress the tree and it may not survive the following growing season.
Knowledge of summer and winter pruning, when taken together with other concepts and factors that direct pruning such as available light, ventilation and the difference between drive and stop cuts, gives the orchardist the confidence and framework to tackle any pruning job.
For professional permaculture design and orchard care please contact Paul Lynch on 089 2553096 or email firstname.lastname@example.org.