you start your seeds inside...where they can be nice and toasty...
then as soon as the last frost hits...you plant your seedlings...

perhaps If you faricated a little green house on the porch using plastic...you could keep them warm and enhance the shorter day of sun with a 250wHID lamp. that's what I do...

This winter I am do my 1st winter nursery hydro growing... I am doing a start-up to an experimental station for my website...Can you say tax write-off? Goodluck, let me know how your doing, peace