Heat and light

[mrskp]

Sam, why don't you get one of those max/min. thermometers which you can leave in the greenhouse & it will tell you what the overnight temp. is as well. I got one a couple of years ago & it cost about �10 but you might be able to get hold of one cheaper.

and then it will tell you that during the day when the sun is out, even in february the internal temp can reach 90o !

[kittykat8]

It is very mild at the moment in Cornwall, I measued the temp in my polytunnel last saturday and the door was open and it was 65 with the door shut it would have been a lot higher I think.

If it need to be above 6 for plants to grow does it matter if ythe temp fall below 6 in the evening.

thanks
marion

[nick the grief]

Not really so long as it doesn't go from 65 to -32 Ideally what you want is to keep the night time temp as high as possible then keep it as cool as you can during the day. That way you get nice compact growth but unfortunately we can't really do that so go with what you've got.

[pigletwillie]

Be careful of letting night time temperatures get much below 10 degrees otherwise it will shock and therefore check young plants and can affect the yield quite dramatically.

A miminum temperature for tomatoes etc would be 10 degrees, any less and the growth is virtually non existent. A heated greenhouse is exactly that, heated. Tender crops if you grow them this early need that heat and if you cant give it to them you may want to wait until later to sow or risk having poor performing stock.

You pays you money and!