I'm up by Lake Ontario, so it's zone 5-6. Last year I started my tomato seeds at the beginning of April, partly because the weather here wasn't going to warm up as early as usual. If I feel like it's going to be a warmer spring, I might start toward the end of March. I'll pot up a couple of times.
Keski

.I live in Kentucky so I think March will do.Thank you for your help.
Nancy

The way to do it is to find your LFD ( Last Frost Date) say on 90/10 probability. For example, mine is around April 1st.
Now dig into the historical temperature around that LFD. I get like lows in high 30s and highs in low 50s. Not a great tomato weather Bu I can start hardening off.
Now I count backward about 7 weeks from April 1st and I am at Feb. 7th. That is my bench march to start seeds. I can even start 2 week after that.

Zone numbers are descriptive of winter conditions and "Cold Hardiness" Issue. So when it comes to summer gardening, those numbers have very little meaning to me. But when hear "Zone 6", eg, it tells me of relatively cold winter and shorter summer (~ 6 months frost free).
There is a more meaningful zoning called "Heat Zone". This one tell how the summer will be like, in terms of temperature. I am in USDA 8a but my HZ is "1". Dallas Texas is also ~ in USDA 8a but in HZ 9. Which means there will be 121 to 150 day of highs over 85F.

Seysonn

Agree. Rather than just guessing learn to ID your average last frost date and your safe transplanting to the garden date. Then start your seeds 6 weeks prior to your last frost date in your location. Depending on how you start them, plan to have to transplant them at least once into larger containers before putting them in the garden.

You'll find much more info about this in the FAQ here and on the Growing from Seed forum.

Dave

Here is a link that might be useful: FAQ

I am in zone 6A in Southwest Ohio. Most of the people that I know in my area plant their summer vegetable gardens on Mother's Day weekend. I usually start seedlings 6-7 weeks before that.

This post was edited by Christacharlene on Fri, Jan 16, 15 at 23:22

I'll be starting mine in late March for a mid to late May planting.

Rodney

Thank you for all your help.
Nancy from ky