In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes

The instructions on the packs all tend to say germination times up to some
months. Is it correct that it should be OK to keep the seeds in their
pots/trays in a 'sealed' plastic bag for that long?

Not if the plastic bag is not clear - some seeds are likely to germinate
earlier, and they'd need light. There's also more chance of damping off
if you leave them in sealed conditions.

When I'm not using a heated propagator I cover the "trays" (recycled
plastic ice-cream cartons) with clingfilm. Then one can see when the
plant have germinated.

For pots, I sometimes use half a plastic lemonade bottle as a mini-
cloche.
--
Stewart Robert Hinsley