Ive read that theres two charges, cultivation is the lesser charge, and production which is a serious charge for more commercial operations. I belive the production charge is the same charge you get for producing synthetic chemicals also, so you relly dont want to get stung with that.

A lot will depend on surrounding circumstances, but I think 6 plant in soil with one light would fall under the lesser charge, where as 12 plants 3 lights and a hydro set up could be classed as production, because you couldnt realisticly say it was all personal.

This is by no means fact, just how I understand it.