Grace (Brenda Blethyn) is a middle aged widow just burying her husband as we meet her. We soon find out that his death was probably a suicide, most likely because he'd accrued massive debts - which he's now left to her. But this isn't a tragedy, it's a comedy: Grace's way to save the house she loves is to grow pot - because growing plants is what she does best.
Blethyn is quite good, as she usually is - in fact, all of the acting is good. But the plot is, well, silly. Very silly, as evidently marijuana turns you into an utter babbling idiot and that's just hilarious on screen ... or not. It was cute, it was somewhat amusing, but I wouldn't really recommend it.