New to greenhouses

[AuntPol]

Hi Folks,

I have a brand new greenhouse and intend for next year just to grow flower seeds for the garden.   Can anyone tell me

(a) what temperature the greenhouse should be kept at for the seedlings from sowing to planting out in spring/summer?

(b) is it possible to purchase a non-electric greenhouse heater with a thermometer?

I would truly appeciate any help that can be given.
(I have also placed this question at Gardeners Corner forum just in case)

[ideasguy]

You can grow quite a lot of plants from seed in a cold greenhouse, Annie (a greenhouse with no heater!).
I would recommend buying an undersoil heater instead of running a heater 24x7.
It needs a bed type construction. I made mine out of wood (sides) and slabs at the base and cover it with sheets of glass.
Its also good for overwintering plants.