Yes at that cool a temperature they won't do much growing. Could you make a little micro climate for them outside. Perhaps put them near a wall and make a 3 sided structure with plastic and a few pegs and leave the top open. You don't have to make it too tall, just a bit taller than the plants.That will harden them off and draw some heat on a sunny day, but youll have to watch it doesn't get too hot. Perhaps some way of opening a side might be good.

I have a shelf that has a plastic zip up 'coat' that fits over it (a $35 greenhouse), but it is VERY hard to control the temps. I have been using it, but i now have too many plants.

I have an old storm window i can probably do something with. And i think i'll just have to accept that I might have to wait an extra week longer to sell my plants.

Thanks for your feedback.

Waiting an extra week to sell may not be a bad thing for your customers. When are they going to be able to (realistically) plant tomato plants in Minnesota?

Average last frost date is May 15th. I usually wait until Memorial Day. But everyone is anxious because we've had the warmest March and April in the history of record keeping.

It's in the low 60's today. I put them outside, but took two storm windows and propped them up against the house. It upped the temp 10 degrees. I'm thrilled! Made a little greenhouse.

I still plan on selling them a week later though. Too much anxiety trying to get them out earlier isn't worth it.