For more information, visit: br The first choice any grower will have to make regarding their plants is: which strain of marijuana do I want to grow?br br There are many differences between one strain of marijuana and another. However they all belong to three main groups, Indicas, Sativas and Ruderalis.br br Indicas tend to be a heartier plant, they developed in central Asia between the 25th and 35th parallel. They are more forgiving and can withstand harsher climates better than most Sativas. They have a shorter flowering period, averaging 8 weeks. br br Sativas are found all over the world. They are a more temperamental variety, and are very sensitive to fertilizer as well as changes in temperature and humidity. Sativas have a longer flowering period and can take up to 14 weeks to fully mature.br br Ruderalis are a wild variety of auto-flowering marijuana that starts to produce flowers as soon as growth begins.