Germination Box

I built a germination box inside one of my greenhouses to germinate seeds without having to heat a large area.  The box is insulated with 3/4" foam board and 3.5" fibergalss insulation.  I lay sleeping bag across the top of it at night to add even more insulation and make it easy to heat during the night.  I have been experimenting with heat sources.  Last year I used a small ceramic heater and it worked perfectly but my goal is to have a heat source that does not require electricity.  I purchased a small ventless propane heater and plan to try it this winter.  

If you have any questions just let me know.......  Stimey