Few roots on the outside edge of the root ball indicate quality

The media has been partially removed on this 25 gallon container oak exposing roots inside. Tree was planted from a 15 gallon container 6 month ago. This high quality root ball has many small diameter roots throughout the ball. There were few roots on the outside edge of the root ball circling around the container. The air root pruning provided by the container design dramatically reduced the amount of circling compared to a regular plastic container.