Deciding to grow a crop of marijuana means the grower will need to make some necessary preparations if the crop is planted indoors or outdoors. The first is to choose the location the crop will be planted, and if it is in the house the grower needs to choose the area carefully. This means a room that will have no traffic, a room where the windows can be closed off without arousing suspicion by neighbors or passersby.  Attracting attention is not what the grower needs, this also means odor from the plants that can filter out of the house and through the house.

Covering windows is usually done with dark plastic, not only to shut the outside from seeing in, but also because there is time when the plants will need complete darkness. This means they need a lightproof growing area to mature properly and at the same time the black plastic keeps neighbors from seeing the fluorescent lighting on for many hours a day.

The room also needs to be reflective, and most often means a coat of white paint, when that is not possible there are other things that can be used, like aluminum foil and Mylar.