The media has been partially removed on this 15 gallon container oak exposing roots inside. The tree was planted from a one gallon container 6 months 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 holes in the wall of the container (see container at right) dramatically reduced the amount of circling compared to a regular plastic container. Each one of the knobs on the container has a hole on the end providing air to the root system that resulted in pruning the roots.