By Flintstone
East Sussex,
United Kingdom 
When a tray of seeds needs to be covered with a plastic bag, does it need to be covered all of the time or can it come off during the day when hardening the seeds off?
1 Apr, 2012
Depends a bit what and where you're growing, but normally, the plastic or glass is in situ till germination occurs and is then removed.
1 Apr, 2012