If you don't want to check the growth, put roots into the ground in a circular pattern. I transplant to really large pots with dirt, so what applies to pots applies to garden dirt.

If the roots are really large, I would prune the plant, both root and branch. You will be surprised how little the pruning will effect growth, especially early in the growing season. Even with a radical pruning you have the whole growing season and annuums, in general, make fruit in 90 days.

Thanks for the quick reply. So straight dirt from the back yard in a pot? How about the transition from Flourescent to sun?

I do not like to use dirt for tomatoes, at least not unless it is mixed with perlite, soilless potting soil or similar. The dirt tends to compact and the roots do not have room to breathe. If you can introduce some worms and bugs to tunnel through it, that should work.

Mike