A book titled something like "Winter flowers in the sun-heated pit" was popular among rock gardeners in the latter 20th century. The described facility was designed for the northeastern United States, and especially for growing alpines. A semi-subterranean alpine house is described in detail in Fritz Kummert's excellent "Pflanzen f"ur das Alpinenhaus" (Ulmer, 1989), which combines natural winter heating with summer cooling, planned for Austria. Neither of these buildings, however, would work well unless their site could be prevented from accumulating groundwater in a climate with persistent winter rain. Possibly an alpine house, intended to keep winter temperature barely above freezing, would not suit the tropical and subtropical bulbs many of our correspondents like to grow. I grow very few such species in my Mediterranean house, which has moisture but not temperature control. Sad to see so few temptations in the BX! I saw the Stonecrop pit greenhouse once, but it was very neglected by then. I hope some of its plants were eventually rescued. Jane McGary, Portland, Oregon, USA On 11/1/2021 7:28 AM, Mark Mazer via pbs wrote: > " I remember Frank Cabot's pit greenhouse at Stonecrop in Cold Spring NY" > > Judy.....there was also one at the Ted Childs ( > https://courant.com/news/connecticut/…) > estate in Norfolk, CT. It was not far from his superb alpine garden. > > On Sun, Oct 31, 2021 at 9:59 PM Diane Whitehead via pbs < > pbs@lists.pacificbulbsociety.net> wrote: > >>>> Does anyone use a solar powered greenhouse heater? >>>> >> Not around here. Never see the sun because of the usual winter clouds and >> the neighbour’s tall evergreens to the south of my greenhouse. >> _______________________________________________ >> pbs mailing list >> pbs@lists.pacificbulbsociety.net >> http://lists.pacificbulbsociety.net/cgi-bin/… >> Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> >> > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > http://lists.pacificbulbsociety.net/cgi-bin/… > Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>