A root growth barrier and method for use with transplantable plants is provided. The navigation apparatus includes a navigation receiver for receiving navigation signals from a plurality of sources; a processor coupled with the navigation receiver for determining a location of the navigation apparatus as a function of the received navigation signals; and an interfaceconnector. Various housing portions may be provided for connection to different portions of the spiral, to facilitate the tightening of the spiral and to cooperate with a latchlock system to retain the spiral in tightened condition.