well it depends on strain and type of plant it is too....I would think so....because sativas grow huge so they need lots of root space.....but indicas grow short so they need less space.....thast what im thinking....I think a indica that only reaches to 4.5 feet woudl only need something like 2 feet......even tho its only 4.5 feet it will prodice more bud than a 6 foot sativa in most cases