[Tobiass]

I have been placing my seeds in a seed tray in MPC covered with propagator lid on heated mat on windowsill OR in a pot in airing cupboard with polybag.

When should I take them of the heat?
The propagator lid off?
I've searched through the previous posts and what I am very confused by is what people define as a seedling/germination completed ...
is it when they poke through soil surface OR when they have upright stems but no seedling leaves OR when seedling leaves have emerged. Seems to a completely naive me that there are several stages of early seedling growth until seedling leaves appear and not sure when heat/light become important.

Also what happens if seedlings appearing for some seeds in tray and not others yet. What strategy is required here....

Sorry for my very simple question and I'm sure it's been covered before too. I'm probably missing the point and lack understanding because of my inexperience...my first year of trying and not sure what is and isn't working...

Any help and suggestions as to what has what has worked for others would be very useful.

[Annen]

I usually take them off the heat as soon as they show and put them somewhere a bit less warm.  I leave the lid on but open the vent until its got seed leaves, then take the lid off, gradually moving it to cooler places.


But everybody seems to do thing differently so experiment a bit. 


You can usually put it back on the heat if it stops dead, but if it grows too fast, there isn't much you can do about it.

[mumofstig]

In seed trays, as soon as the first seeds have shown and seed leaves have opened I take them off of the heat and remove lids. The rest usually appear pretty soon. These are seedlings that have germinated - now they need to be grown on.
I leave them on the window ledge and when they are big enough they get pricked out into their own pots or modules. If they are hardy plants they then need to gradually introduced to the outside world.

[gremlin]

Germination is the instant at which the seed decides to grow. The seed will be in its dormant state indefinitely until some internal chemical "switch" is switched on.  You cant switch growth off again without killing the plant.

Problem is that we don't normally know if the seed has germinated, or is a dead one, until we see something poking above the soil.  That's one reason to chit seeds, so you can see instantly the first microscopic root appearing. and you wont waste days or weeks waiting for a shoot to show above the soil, only to find there is no chance.

Many seeds never germinate. Others seeds take their own time.  I have had tomato seeds germinate (same batch, same plant pot) from one week to 6 weeks).  You could always gently dig up a non-sprouted seed to see what is going on.   It it has turned smelly, moldy, squidgy or totally disappeared then there is no hope. Otherwise it is just patience.

What you are asking about to looking after "seedlings".  (Q:- when does a "seedling" turn into a plant??)

Most seedlings like it slightly cooler and less damp air than they wanted in order to germinate, and they want sunlight the moment they break through the soil.  The food in the seed will only last so long, then they must start photosynthesizing 

Less damp air generally means more ventilation, by opening the vents or removing the lid.  But that can create draughts or changing temperatures which are not good.

Science only takes you so far.  The other 99% is experience, trial and error, or luck.

[Madame Cholet]

not very technical but mine come out of the heated propagator as soon as they appear out of the compost as  have a queue for it.