Hi there, we have a sour cherry tree on our new property that was planted 3 years ago by the previous owners and they have never taken care of it, except to provide water and cut the suckers. We would like to give this tree the best chance and need to find out how to go about pruning, and when is the best time to prune. We live in Canada, in zone 3. The tree gets a good half day of full sun. It currently produces some fruit, minimal at best. Thanks in advance!