Once the location for the cannabis crop is decided the grower then needs to prepare the soil, and this can begin between early March and mid April depending on where the grower lives and the planting season. One of the things that is usually done by growers to ensure that they will have a decent start on their crop is to use organic potting soil, which can be bought in 40 pound bags to mix with the existing soil for the outside crop. In areas where there is acidic soil is necessary to add a lime, which will make the soil the right pH level for the marijuana plants to grow in. When the location of the crop is clay mix soil the grower will need to add peat moss into the soil for drainage purposes.

When growing in outdoor crop of cannabis plants it is important when using potting soil that it is sterilized and when using fertilizer that is organic, using fertilizer with chemicals will mean that these chemicals will place toxins in the harvested marijuana.