Cooler temps will slow them down. Do you already have them in the basement with grow lights, or are they upstairs?

For future ref... I start mine in early March, and mine go out into EarthBoxes so can be started earlier the normal anyway. Most folks don't start their tomato seeds until mid to end of March. Mine go out on Mother's Day weekend, but again - into boxes not the ground. You *might* get some benefit with the Walls-o-Water (assuming a bright early May) putting them in the ground then, otherwise they'll just sit there, stalling, until the ground is warm enough. Keep an eye out for rot!

-Marie

I started my tomatoes in March too. I think the biggest problem with starting them this early is not so much the size exactly but the fact that it would be very easy for them not just to get tall, but to get tall and spindly. Last year, I transplanted mine a couple of times between seedling tray and garden. First I transplanted them into 10 oz styrofoam cups and then into 20 oz cups. Each time I transplanted, I stripped off the lower leaves and buried them up to their little seedling necks. I also kept the lights on them 24 hours a day (although I think 12--14 hours might have worked just as well). Keeping a fan on them will also help them grow stronger, sturdier stems. Good luck with them. You'll have to keep us posted on how they turn out!