Posted: 21/10/2013 at 12:59
I suppose the difference between a coldframe and greenhouse is that you can walk into a greenhouse. There is no temperature difference between a coldframe and cold greenhouse unless you use a heater in a greenhouse to keep a certain temperature. So you generally use a coldrame for hardy plants or plants that are hardy due to being kept dry - Agave for example.
I would say a bigger killer than cold is grey mould caused by inefficient ventallation in both coldframes and greenhouses, especially on seedlings. Any sunny day, open the doors to ventillate both.
I started with coldrames and moved up into greenhouses and use both - you can use a coldframe inside a greenhouse to add a little more protection.