Hi Lisa:
I have not had success in our cold winters with WSing tomatoes. This year, I am experimenting with tomatoes in a very protected environment - old cooler, insulated with styrofoam, covered with a glass window - on April 1, but I will also be planting some under lights as usual in late March/early April along with my peppers which I find benefit from the early start. All the other veggies you mentioned I direct sow as soon as it is warm - usually early May here in Ottawa. Good luck!!
Northerner.