[JaK]

I have a greenhouse now but have never used one at the start of the year before. When can I start sowing? Should I be sowing peppers, chillis and tomatoes now? 

[mumofstig]

Sow them indoors, with the expectation of  transferring to the greenhouse permanently at the end of April, beginning of May - according to your local climate

I usually start putting mine out there during the day and bringing them back indoors at night from the start of April 

[JaK]

Thank you. I'll get sowing at the weekend. 

[devonbarmygardener]

My tomato seedlings are in propagator-type covered trays and they are in the unheated greenhouse now.
I got them to come up indoors though.

[DD.]

Tomatoes need a minimum of 10C and it still gets very cold overnight, even in Devon!

The best I can advise is to keep them in the greenhouse during the day, so they get plenty of light, but bring them back in at night.

[JaK]

  Yes unfortunately it does, even day time temps aren't getting higher than 6 or 7C at the moment.. I'll sow some at the weekend indoors for now.