Much like the previous answers, this will largely depend upon the tree. In certain instances where the tree is especially large and there is the possibility of injury to yourself, others or the potential for damage to property then there is no question that a trained arborist should be called in to complete the work. An arborist’s knowledge of trees and legislation will also insure that you don’t damage your tree by pruning it incorrectly or inadvertently break any laws relating to tree preservation. Tree pruning Sydney needs to consider legislation relating to Tree Preservation Orders and Local Environment Plans. With the potential for hefty fines it is best to engage an expert arborist.