In article ,
eptal writes:
|
| 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.

It wouldn't.

In the West Country, houses were (and probably are) built without
room heating, as it was and is largely unnecessary. But they did
have fires and airing cupboards, which used the heat to reduce
the relative humidity. You almost certainly have the same problem.

If you can get power there, occasional (SLIGHT) heating to reduce
the humidity temporarily will discourage grey mould. It won't do
more, unless it is done more-or-less continuously.

Another thing that you could try is a small (ultraviolet) tanning
lamp (e.g. one for the face) and leave it on in various positions,
not too close to the plants. I have no idea if it will discourage
grey mould, but it might.


Regards,
Nick Maclaren.