In article ,
Janet Baraclough.. wrote:

Ideally, at some time during a very cold spell, open all the doors
and vents wide overnight to let the cold kill mould spores. Obviously,
you'd need to put any plants in the house or garage while the GH was
getting the freeze-cure.

Are you sure?

Yes, you will kill active grey mould (Botrytis cinerea) that way,
but I should have thought that its spores would take any temperature
this country ever gets to. This is checkable by finding out its
northerly limit in the wild, but my guess is that it extends right
up to the limit of fruiting plants.

That doesn't affect the relevance of your recommendation, of course,
as there are lots of parasites that ARE killed by cold.


Regards,
Nick Maclaren.