A support system for supporting at least one plant contained in a pot is provided comprising a tray having an outer wall, an inner wall defining a receptacle for a pot, and an insulating interstitial space therebetween. The tray may include interlocking means allowing several trays to interlock into a single continuous unit. In another aspect, the present invention provides a support system as described including an integral fluid delivery system for providing a fluid to individual receptacles. A rack system for transporting multiple trays is also provided. In addition, a method of completing an inventory of plants contained in the trays of the invention is disclosed.