For Reliable Seed Germination You Need A Heated Propagator

If you want to sow seeds early before the weather has warmed up enough to allow them to germinate naturally, or even if you want to be sure that seed which is temperature sensitive germinates, then you need a heated propagator.

If you are lucky enough (and wealthy enough) to have a heated greenhouse, then you do not have this problem. The rest of us have to devise ways of warming our sowing medium without breaking the bank.