This technique gives a more natural appearance over other pruning methods and leaves more time before pruning is to be carried out again, this will minimize stress to the tree. However the pitfalls are that the tree will be left with large wounds which can leave it open to pathogens and parasites. When crown reduction takes place certain measures and guidelines are to be taken into account. 30% of the original crown shape should be retained. Crown reduction involves all limbs to be cut back to a growth point, whilst maintaining the natural form and proportion of the tree.