How applicable would your information be to those of us who rarely see the sun in winter? My unheated greenhouse manages to keep itself frost-free but if the sun does come out, the temperature may go up only a degree or two. Diane Whitehead Victoria, British Columbia, Canada cool mediterranean climate moderate dry summers, moderate rainy winters 68 cm rain (27 in) On 7-Jun-12, at 1:08 PM, James L. Jones wrote: > The book presents detailed information on operating a greenhouse > that is heated by the sun alone and on choosing a satisfying array > of off-season bloomers that do well under its conditions,