as an mmj patient you have the legal right to a two month supply of medicine in your possession and to manufacture your own medicine, the minimum amount assumed by the law to keep one patient in medicine is 15 plants and 1.5 lbs of medicine or medicine equal to 1.5 pounds of plant matter, if you are under those numbers you are fine, if you are over those numbers and can prove it in a court of law, then you can grow and have however much you need, the important thing to keep in mind is that your medical need of quantity is up to the judgement of the court.
also keep in mind that if you sell, deal, or in some way benefit from the production or distribution then your medical status is void and probably will not be allowed as a defense for those other crimes, so keep you nose clean and dont be stupid about what your doing, and if your gonna grow more than the 15/1.5 lbs then you need to keep accurate records to show that this is how much you grew and this is how much you medicated on this or that day, cause otherwise the assumption is no you dont eat/smoke/bathe yourself with a quarter pound of flowers each day, but if you can provide records and prove medical need, you could go on the all green diet, eat drink and breathe ganja hahaha