We are in zone 5 but you have micro climates to work around too. Possum Run Rd in Richland County? is the coldest spot in Ohio on a regular basis but go up by the lake and it is more temperate or down south farther... much warmer, but I don't plant out without the anticipation of having to cover ever until June 1st. The earlier you start the more you have to babysit the plants. we had a freeze last May on the about the 15th. I think the frost date for us is about may 15th, but we have had frost much later than that on a regular basis (so much for all the global warming).
Around here we buy the things we want and keep it in the garage until the weather warms...otherwise everything is picked over and you can't find what you want...Our freeze is late too , not sure of the date.
That's a good idea Sherry. I have read that if you surround your tender transplants with 2 litre bottles of water, you can put plants out before the last frost date. Of course who would want to surround their petunias with coke bottles!?? But I do think I will experiment with this by planting a tomato or 2 surrounded by bottles of water. I'll see how they do & compare them to tomatoes Put out after the last frost date. Guess I am channeling @Jerry Sullivan here.