This technique is used to prevent wind damage and let more air and light through the canopy, still maintaining the size and shape of the tree. Thinning should not be excessive or cause large wounds and a limit of 30%. Taking in to consideration times of crown thinning the maximum should be removed in one season
Crown thinning involves the removal of a proportion of secondary and small live limbs throughout the crown reducing the density of foliage. Thinning should be well spaced and balanced in order for a good limb structure.
Improves health of remaining branches
Protects the main branches from damage
Reduces weight of the crown
Removes potentially dangerous branches (prevention is better than cure).