This is a reduction of the height and/or spread of the crown of a tree. By reducing the size of the crown you can in turn reduce the amount of stress put on branches. The tree has less sail area and so therefore is less susceptible to wind. Crown reductions can often be a good tree management option if the tree has outgrown its immediate environment, for example a small back garden.
The aim of a good reduction is to create a smaller tree whilst at the same time retaining the standard form for a tree of its species. All pruning cuts should be brought into growth points (live branches) to reduce the chance of limbs dying off. Reductions should be specified by actual measurement especially is the tree is TPO’ed or in a conservation area and the work needs to be applied for. For example ‘crown reduced in height by 2.0m and 2.0m lateral spread.’
Different species react differently to being reduced so it is best to ask the advice of a qualified Arborist before making a final decision. Crown reductions should not be confused with ‘topping’, an outdated method of pruning which is detrimental to the tree. It is important that all work is carried out to BS3998 – the British standard for Arboriculture.