Propagators

[Piglet]

Can someone explain how to operate one of these please, cant seem to figure it out.  I've got one, heated no thermostat on it just plug in and go, the lid has 2 slidy vent things.

Ive cleaned it thoroughly, switched it on
Dampened the fabric thing that sits on the base
sown seeds in pots, watered / drained them put them in
vents are shut

then what  

ive had it for 2 years now and not really used it much as keep mucking it up, last year i had very leggy tomatoes in it?
as soon as the seeds germinate am i missing doing something ?  

Piglet.

[Hugh_Jones]

If it hasn`t got a thermostat it probably gets too hot during the day - particularly if it`s in a heated house - and this alone will `draw` the seedlings.  Additionally, any small seedings under a plastic lid will tend to `draw`.

As soon as the seeds germinate get the vents open - this will reduce the humidity and the temperature - and, if the propagator is in a reasonably warm situation, get the lid off, or the tray of germinated seedlings out, as soon as reasonably possible afterwards, and expose them to full daylight

[The gardener]

You could invest in a small soil thermometer, this helps.

At least you will have some guidance as to when to let cooler air in or not.

[Mrs Ava]

I have a heated propogator, had it for years and years.  It doesn't have a thermostat either.  I have never used it for growing seeds, only for cuttings, and it works a treat there.  Cuttings take in no time and there is plenty of humidity.  I keep the vents closed until I know things have started to root, then I open the vents during the day and close them at night - almost like hardening off - until eventually, I unplug it and take the lid off.  No idea if this is good, bad or ugly, but it works for me!  

[Hugh_Jones]

That`s Exactly how cuttings should be struck in a propagator EJ. The difference is that with cuttings, which are much firmer plant material than seedlings, and have been semi-comatose while rooting, new growth begins more slowly, and a few days, or even a week or more, delay in removing them from the propagator doesn`t make much difference. With newly emerged seedlings, on the other hand, even two or three days too long in propagator conditions can make all the difference between short sturdy seedlings and long thin leggy things which are of very little use.