Here I where live in Tennessee, most people are happy if they can harvest a fresh tomato by the 4th of July. This year we harvested our first red tomatoes on May 11!
Tomatoes are relatively easy to grow from seed. We often start a few in February, up to two months before the last frost date when it is safe to plant them outside. We plant the seeds in small pots and place them under grow lights as soon as the plants emerge from the soil.
However often we let someone else do the early work, and this year purchased two plants about a foot tall from a local greenhouse in mid-March.
As the plants get taller, we can continue raising the grow lights as high as necessary, always keeping the lights 2-3 inches above the plants.
We will transplant two to three more times as the tomato plants get bigger, moving them to larger and larger pots. The final pot will be about 10 inches in diameter and 10 inches deep. Eventually the plants get so tall they need staking!
As soon as possible, when the days are warm and there is good sun, we will set the plants outdoors during the day and bring them in at night. This helps "harden off" the plants, making them more used to an outdoor environment so they doesn't go into shock or grow tall and spindly. In the beginning, we'll set them outdoors for just an hour or two, eventually increasing to full days. If outdoor temperatures do not go below freezing at night, we will place the plants in our greenhouse and let them stay out there both day and night.
This year our area had a relatively late frost (April 20). Fortunately we still had not set the plants in the ground and were able to bring them indoors. We did not actually plant them in the ground until around May 1. There were many flowers and a number of green tomatoes already on the vine!