Hi Adam,
I start my tomatoes and peppers in the house, on a heat mat with light, in front of some windows. Once they have germinated completely, but before they get their first true leaf, I move them to my unheated
greenhouse. Too long indoors, even with lights, and they get soft and leggy. Trying to germinate them in the
greenhouse is just too cool, especially for the peppers. What I have developed is the best of both.
My dates look like this-
April 1 sow seeds in flats indoors
April 15 move flats to greenhouse
May 1 transplant from flats to small pots
May 25 transplant to outdoor garden (more like June 1 for the peppers)
Hope that helps, good luck!