Hi geoff and sam
The greenhouse is unheated but have a paraffin heater for when i try a few seeds later in the year.
You get the odd frost at night here anytime between jan - jan BONNIE SCOTLAND
.
Anyway will give the peppers and chillies a go in the troughs.
I spoke to the garden ( EXPERT ) at the local garden centre yesterday ,told me would be best to grow some tomatoes in pots in good quality growbags and leave the troughs for other things .
Maybe just trying to get me to buy some of thier bags ? 
Anyway thanks again for the tips i have enjoyed reading all the questions and answers on gardeners world over this last year ( my first ) and am sure i'll be back soon looking for more help.
Mike.