I have a mini greenhouse which works really well but don't start any seeds off until the weather has improved considerably, usually May time.

If you grow them indoors, you need to put them on a windowsill where they get as much light as poss. Still a bit early with this weather, I usually start mid march but shall wait until this is over.

You don't need to heat your whole greenhouse you can buy an electric propagator.

I use heated propagators but often dont start them off as early as the packet says as they often get too cold when too big for the propagators.

Hi SBG what do you mean that " they get too cold" ? Where do you put seedlings when you take them out of propagator? Is that why you start later due to it being ( should be) warmer, then you can leave them in the greenhouse.

Exactly that Pdb when they come out of the propagator if the air temperature is too cold in the unheated greenhouse it can set the seedlings back. The seed sowing advice on the packets often suggests times that are far too early.

yes especially in the north. I go at least 2-3 weeks later.

I think we all do round here SBG. In common with a lot of gardeners I start to get growing fever around now and of course last year we were all tricked by the weather into thinking that summer had started early and was going to be fantastic. Good job I didn't promise everyone free fruit based on all the insects in mid-late March, it was the worst year ever. The seeds I put in for early germination all sprouted like mad and then keeled over and died in April. :o((. On propagators by the way, if you are watching the pennies, and who isn't nowadays, then you may get lucky like I did. I got a large, low power (about 20 watt) prop at a car boot for £3.00. :o)). As everyone else says though you have to be careful that when they are ready to come out you have somewhere at a comfortable temperature with ample light to put them. Grow lights are good but, if you can't rig up the newer LED ones, are expensive to run.

Unfortunately there is no substitute for heat in your greenhouse.
Mine is kept ticking over at no less than 50'f which is fine for this time of year.
A large heat mat, about 6ft x 20"is what I have, with a thermostat, has the power rating of a 130 watt light bulb.If it is on all day will cost about £8 a month.

Thanks for all your replies. I guess I have been to eager. We normally go away for most of the month of March and last year badgered my hubby to bring it forward as its a rush getting all my seeds and beds sorted. I guess its backfired on me this year. The problem also is I have used most of my seeds :-( . See picture below.