Okay I got all mine from friends 47 to start collect over 3 days out of unheated chicken coops with 14degree f temps outside they toldme nit to get my hopes up but I am on day 16 have 45 growing only one was infertile and one I dropped while candling at day 7 oh also just asked my brother and he told me he keeps a 25 w light bulb on in the cardboard box at night so I'm guessing the heat the light produces helps keep the inside of the boxes temp more stable