I have the peas and lettuce and a few of the other more cold-hardy plants transplanted and in small pots already, sitting in a few flat boxes so I can move them out. It's super sunny, very bright direct sun but still kind of cold. With the full sun, at what temp would you set out the hardier vegetables during the day?

Direct sun exposure and wind are the primary enemies to young house-grown seedlings so their exposure for the first few days has to be limited and protected.

So as long as it is well above freezing, find a shaded or dappled sun location OUT OF THE WIND and give them an hour or 2 exposure with close monitoring. Next day if all goes well you can go to 2-4 hours, etc.

Experienced gardeners will tell you that once your plants are fully hardened off they shouldn't come back inside as it only sets them back once again. So most of us won't even start the process until a week or 10 days before they can go into the garden. How long until you will be able to plant these in the garden in your zone 3? Since zone 5 growers are just now setting out their cold- hardys I'm guessing a month or more for you, right?

Dave