Hi, this is my first post to this site, so I hope you will forgive me if this problem has been covered before. Every year the overwintering plants in my unheated greenhouse suffer from grey mould. I make sure that the plants are not too close together and that the greenhouse is well ventilated, although up here in Morayshire most of the air going in is fairly damp. I wondered if there was a spray someone could recommend that might prevent this, as I am a bit wary about using sprays on dormant plants. I tried green sulphur powder last year but it did not have much effect.