THIS INVENTION CONCERNS APPARATUS FOR GROWING PLANTS COMPRISING A COLUMN 100 OF POTS 102 STACKED ONE ABOVE THE OTHER TO DEFINE AN ENCLOSURE FOR HOUSING PLANTS. EACH POT 102 DEFINES A CHAMBER 104 FOR HOLDING A PLANT. SEPARATORS FOR SEPARATING POTS OF THE COLUMN ARE PROVIDED AND THE SEPARATORS DEFINE AN ENCLOSED HEADSPACE AROUND A TOP OF AT LEAST TWO OF THE POTS WHERE PLANTS PROJECT FROM THE CHAMBER. THE CHAMBER COMPRISES A PASSAGEWAY 106 THAT PROVIDES A CONTINUOUS FLOW PATH FOR AIR THROUGH THE COLUMN 100 WITHOUT REQUIRING THE AIR TO FLOW THROUGH THE CHAMBER 104. THIS FLOW PATH INCLUDES THE HEADSPACES ABOVE THE AT LEAST TWO OF THE POTS 102. FIGURE 1