if it is frozen then there is no point. as a rule keep them on the dryside anyway as cold/wet is the main cause of death of plants.

If the soil is hard and dry, ie frozen, then you do not water. In fact, in this weather try not to water anything.

I thought by putting them in the plastic frame it would keep them safe but in this extremely cold weather I guess it hasn't worked.
Thanks for you help, it's much appreciated

What you could try is getting a very small green disc paraffin heater clear the bottom shelf place the heater there and this should keep it above freezing and the plants should survive see link below as the sort of heater that springs to mind.
http://cgi.ebay.co.uk/1-X-PARASENE-COLD-FRAME-MINI-GREENHOUSE-PARAFFIN-HEATER_W0QQitemZ110618829585QQcategoryZ131612QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D15%26pmod%3D140382720573%26ps%3D63%26clkid%3D5397875724918750270

Steve

I also forgot to add buy a fleece for your greenhouse look on ebay they are very cheap

I bubble wrap my main glass greenhouse with the proper clips and my little plastic one I just stick bubble wrap all over it with that very sticky brown parcel tape. Same idea as Steve's but as I had wrap but no fleece left it just saved a bit. It works, but a bit late now.

Thanks everyone, I guess I have left it too late Sarraceniac but IF they survive I will do all those things for next winter. I do have fleece around most of the bigger posts but not all over the actual 'greenhouse' itself....never thought of that! As it is only December I may still do that though, we still have lots of winter weather to get here in Scotland. Thanks for you tips Steve and link to ebay site, very kind of you.

I just bought a heater and extra fleece to cover the frame on Ebay, many thanks to all I'm so glad I found this site for advice.

i buble wraped and clued plastic on the out side and still had frozen plants urggg