Posted: 15/11/2014 at 21:06
Unfortunately, sweet pea seed react by taking off like a rocket if subjected to too much warmth...resulting in spindly & weak seedlings.....certainly wouldn't use a propagator myself.
Probably best if you transfer propagator and seedlings (don't know if it's heated or unheated) into a cold greenhouse or coldframe straight away. Leave the lid off during the day & replace it at night for a week or so......thereafter dispense with the propagator altogether, just leaving them in the cold greenhouse or coldframe.
PS. Of course don't switch your propagator on, if it does happen to be heated.