I am going to transplant some Phoenix Canarienesis. The are in the ground. The trunks are 2-3 feet high and 3 feet wide. The crowns are 5-7 feet. Very healthy. My question is to anyone with experience transplanting these. How much of the root do I need to take with the tree. I.e. how many feet or inches past the trunk or root ball and how deep. Thanks.