Cold frame questions

[Dreaming]

What is a good size for a cold frame? What materials would be best for a partially buried cold frame? What would the average increase in season be in zone5? These cold frames will be facing straight south, with a garage to the north, a tree to the s.east and open to the west.

[Flower_Man]

The size of the cold frame should be matched to your space requirements. a full cold frame holds heat longer than an empty one. The absolute best material for a buried cold frame is concrete insulated on the outside with polyurethane foam insulation. The concrete will store the solar energy accumulated during the day. For a covering double wall polycarbonate or arcrylic panels would be the most efficient. A general rule of thumb for unheated covered space is that they gain one temperature zone. Thus a zone 5 would become a zone 6. The insulated concrete frame might gain another zone thus your zone 5 could become a zone 7. The location you have picked sounds like the best possible.

[Flower_Man]

Good site for all kinds of agricultural plans

http://www.public.iastate.edu/~mwps_dis/mwps_web/frame_p.html

[Flower_Man]

One more

http://www.ag.ndsu.nodak.edu/abeng/miscplans.htm

[Flower_Man]

Last one

http://www.ag.ndsu.nodak.edu/abeng/cropsplans.htm