Posted: 24/02/2012 at 17:32
Hi anthonyhazell, it depends on the plants, really. It's a good idea to take the lid off the propagator a couple of weeks after germination, especially if condensation is building up, which can lead to fungal infections developing on the plants. If your seedlings are in a heated greenhouse then they should be warm enough. Perhaps you could acclimatise them gradually, by taking the lid off the propagator and leaving them for a few days, then potting them into seperate pots but leaving them in the greenhouse... then, eventually, when all risk of frost has passed (depending on how hardy the plants are), pop the plants out in the day time and bring them in at night, before eventually putting them outside. Hope this helps!