The best time to prune your trees depends very much on the species of the tree. When in doubt over what time of year would be best for the tree species in your particular yard, a call to a certified arborist will clear everything up. When pruning, it is always important to remember that all pruning cuts should be made outside of the branch bark collar to ensure that the pruning wound will heal correctly. When choosing a tree service, ask if work is performed to American National Standards Institute (ANSI) standards. This will ensure that all pruning cuts made are done according to the most widely accepted & accredited tree care guidelines.