On March 16, 2015. Temperatures stared to drop into the high 30's F
So, I went ran outside and added a plastic cover to the top of the bed. This allowed me to control the soil temp decrease. It only went down to 48f . The next day I did this video. (March 17)
March 19, air temps 42° | 35° soil temps 49-50 rain fall .11 inch
Today March 20. air temps 55° | 43° Soil temps 50- will put in the number when I cover the bed for the night.
Note. This bed contains potatoes I started from Pull sprouts.