Beginner Gardening: Tomato Questions, 1 by TXBBQ

TXBBQ wrote:
I would like advise, please, on when to transplant tomatoes from starter peat pots to my above-ground garden. I am using the (organic) "All New Square Foot Gardening". Planted seeds directly, but they did not grow at all. Don't know why. I did get a late start (end of May) but I was told that shouldn't have been an issue.

In the pic, I have Brandywine's and Romas in the peat pots. It seems too early to transplant them now, but is this the time to begin putting them outside for a little while to "harden off" as I've read about?