That's a funny one to answer these days, partly because i'm not quite sure on the law and partly because the cops are playing a bit funny atm. Just this christmas period, customs at heathrow were instructed not to search for drugs as they couldn't spare the resources. Alongside that the sheer number of people who are getting bsuted and being given a bit of community service and little else. Jailing anyoe and everyone for cannabis is finally catching up with them.
That aside the grow would still need to be kept to a scale where a landlord coming over would not notice it from noise, smell or sight. You basically need to be able to show to the jury that you had no prior knowledge of the growing. If you are infront of a jury though, it means that the place has been searched by the police already, which means it was under surveillance, which means they will have recorded you coming and going from suposedly someone elses home, to which they'll demand justification for the frequent visits.
Short story is i think it would be doable, but only upto a certain level, at which point the jury would say bollocks to that, you obviously knew or were the guy in charge, and then it would come down to how badly they feel the need to lock you away etc is, which as i say is seemingly a lot these days, you can get away with a fair bit without jail.
That also said, these light punishments are because people generally fully comply, if you start pulling them around with red herrings and false identities and such, and they see through the chirade, they may very well fuck you over for trying to take the piss, and possbily do you for a bunch of other serious offences such as preventing the course of justice, falsifying documents etc.
