Hi Colleen, Well, I think we're all rooting for you to have your solar greenhouse, and I suggest it might be feasible if you adjust your expectations, settling for the hardier kind of winter-blooming plants. Basic shrubs would be Camellia (fall-blooming sasanqua hybrids are best to be sure of flowers in the dead of winter), Daphne odora, Indica azaleas, etc.; well-tested bulbs include Narcissus bulbocodium praecox, N. 'Nylon', and N. fernandesii later in the season. These all can take 20oF if planted in the ground; in pots the roots are vulnerable to freezing if the cold lasts too long. Overnight has been okay with me. An efficient way of protecting the pots is to place them thickly on a heating mat that is controlled by a thermostat. Water as a thermal mass is dicey if the temperature is too low for too long, which is to say if surface ice doesn't melt off during the course of the day. Anti-freeze is not out of the question, or an aquarium bubbler to keep things stirred up. Go for it! Jim Jones Lexington, MA -----Original Message----- From: Colleen <email@example.com> To: 'Pacific Bulb Society' <firstname.lastname@example.org> Sent: Mon, Jun 11, 2012 10:09 am Subject: Re: [pbs] New book Well, I tried water, though not drums full because of door size and I do have a crushed rock floor. Our climate is very unpredictable in these days of change, but two winters ago we were back down to -22F (-30C) and we have gotten to -32F. This year we only came close to 0F. Electricity is quite expensive here so I can't afford a heater that would run 24/7. Ventilation and mold are also a problem with the cold air. Thanks Colleen in NE Calif. -----Original Message----- From: email@example.com [mailto:firstname.lastname@example.org] On Behalf Of Alberto Castillo Sent: Sunday, June 10, 2012 1:58 PM To: Pacific Bulb Society Subject: Re: [pbs] New book Colleen, not even a lean-to one? You have the black painted water filled drums resource, that is excellent, also a crushed rock pit instead of floors, etc.