I would be very careful about growing in a rental property, MMJ license or not. I have not seen any laws (correct me if I've missed it) that protect a renter in that situation. There are however many regulations or lease stipulations that can be used against you if the landlord wants to be an ass. If the grow were discovered and the landlord freaked out and called the police, you can bet you'll be evicted. Even with a MMJ license the landlord could always use the defense that you did NOT disclose the fact that you were going to grow before you signed the lease. Another reason why you want to be upfront (and that's not easy I'm sure) is that of insurance liability. If a fire ever broke out and the Police/ Fire department deemed your grow as the cause, (poor design, electrical fire, etc...) you are busted for sure. I have even heard of landlords being denied claims due to fire from meth labs that caught fire and burned the residence. While meth labs are def illegal activity and MMJ may not seem like it, it still is illegal at the federal level. Your very best bet would be to talk to a 420 friendly lawyer, Robert Corry from Denver may be a good choice for that. Good luck!