Planting tomato seeds from fresh tomatoes requires the same gardening method as planting tomato seeds from a package. After removing the tomato seeds, give the seeds a quick rinse to remove any tomato juice from the seed. The tomato seeds are ready for gardening and should be planted within seven days of removal to prevent the seeds from contamination.
Fill the seed trays with the potting mixture.
Plant the seeds 1/4 inch deep in the potting mixture. Give each seed its own individual section.
Cover the seed tray with plastic wrap for seven to 10 days. This process is the germination period -- a process that softens the shells to assist the sprouting of the plant.
Remove the plastic wrap once you see the sprouts appear above the soil.
Expose the tomato plants to sun for three hours a day, increasing the increments by 10 minutes each day until they have six hours of sunlight every day. Gradually exposing tomato plants to the sun prevents sun damage.
Water the plants after the soil dries. Over watering a tomato plant causes root-rot -- an irreversible and deadly disease. Under watering stunts growth.
Transfer the tomato plants to pots after the stalk is 2 inches above soil. Use the same potting mixture.
Tie the stalks to a stick with twine. The stick forces the vines to grow upward, allowing the fruit to grow abundantly.
Remove the lower leaves from the tomato plant as it grows to induce ripening of the fruit.