12 is more than enough for any household's personal use ... like people mentioned just grow fems or clones... or start early indoors and sex cuttings from young plants so you can cull the males before dedicating them to your plant count
... it does raise an important question though .. do males count? ... in that case I suppose if someone was busted for growing more than 12 (and had reg seeds going), they could take a genetic sample and use a lab like farmer freeman to determine the sex of the plants to determine exactly how many fem/males they have ... but Id also be curious to know who's burden it is to perform the tests? ... I'd actually think it lies on the state to prove that the plants are female and will produce thc... otherwise there's a whole lotta reasonable doubt that could be raised by defendant
