Where can I find information about the temps needed for certain seeds? I have just planted outside in a raised bed beets, kohlrabi, rainbow swiss chard, green onions, carrots, parsnips, and several kinds of lettuces. Those cold tolerate veggies don't seems to mind cold soil temps and I have had no problem with them germinating in the past.

I just got a greenhouse and have planted 12 trays of herbs and flowers which I will put out in about 8 weeks. Since they are more tender, that is why I started them in the greenhouse, I was wondering if I would need a seedling heat mat. The greenhouse's lowest temp so far has been 40 deg. at night and 80+ deg. during the day. I have a vent fan on order to cool it down. I have a couple of books on order but I would appreciate any information about seed & soil temperatures now.

Thanks.

Clare