Air Pot containers are designed to air prune roots by guiding their tips to open air, through holes in the pots wall and base. Air Pot's open wall and floor permit high oxygen permeation of the growing medium. Very fine root tips are guided to open air at the cusps of Air Pot's walls where they lose apical dominance. Root branching occurs well back within the root ball and several new roots grow to adjoining cusps. The process repeats at an accelerating rate until the growing medium is colonised with fresh new roots. When all of the medium's pore space is filled with roots, root growth slows. Growth of the head of the tree also slows in equilibrium with its roots system. Trees can be held safely in Air Pots for much longer than normal pots. The roots do not spiral and plants look healthy. When the Air Pot is removed and the tree is planted, the abundance of active roots grow outwards and downwards to colonise the new site.
