The Pansys and Penstemon can start hardening off in the middle of May. The Penstemon takes a long time until it blooms so I have to start them pretty early. I usually put anything that is even slightly hardy in my little trailor and pull it in and out of the garage according to the weather and how much space I have under lights.
I usually get ahead of what I should when starting some things cause I'm ready to be gardening but the weather isn't!