Humidity control is important and in some cases where the grow area is larger than a closet it is necessary to use a dehumidifier, this is because humidity will cause the growth of wide leaves and there will be a reduction of resin produced. The leaves when laden with humidity cannot dry fast enough and that makes it more difficult for the plants to grow properly.

 The grower is usually concerned with the quality of the crop and that means having narrow leaves and more resin, this can only occur in a grow room that does not have a high level of humidity.

The theory is that the cannabis plant will produce more resin when the room has less humidity in order to keep their leaves protected from drying out. In effect, what this does is cause the ganja to grow with narrow leaves that are protected because they are coated with resin and that makes a quality harvest.