In article , Janet Tweedy
writes
In article , Alan Gould
writes


If we want to push a raised bed on a little early, we cover it after
seeding with a sheet of clear PVC. We weight the sheet down to prevent
it blowing away and we remove it as soon as small seedlings can be seen
pushing up under it. That reduces germination and growing time by 7-12
days depending on circumstances.


Doesn't the weight flatten the seedlings?

We ensure that the sheet is not pressing tight to the soil. The holding
weights are beyond the sowing area. We leave the sheet on as long as
practical, but not so long as to inhibit growth of the seedlings. The
only tricky bit can be a hardening off one if the weather suddenly turns
colder at the time when the sheet is due to come off. Even in that case
the growth rate of the seedlings slows enough to allow the sheet to
remain on until the cold snap passes.
--
Alan & Joan Gould - North Lincs.