Its ok for now. The mangoes are 6 feet apart which is the same spacing used in many high density mango plantations in India and other countries. Some even plant 900 trees per acre. Dr. Campbell and Cecil have many mango trees on 6 foot spacing, some less. Those are commercial plantations, I'm growing for personal consumption only. I enjoy having numerous varieties as well as pruning and shaping the trees. As of now I havent run into any problems but worse case scenario I have to remove a few trees in the future. For now I'm enjoying the ride.