Fill peat pots or plant trays with moist seed starter five to six weeks before the last expected frost in your area. This allows adequate time to produce vigorous, young seedlings ready for outdoor growing.
Plant one to two seeds per pot to a depth of 1/4 inch. Cover with soil and press down lightly to secure the seed. Although only one seed is needed, planting two eliminates worries of occasional bad seed that does not germinate.
Water thoroughly to moisten the soil. Cover the top of the plant trays or peat pots with clear plastic wrap. This seals in moisture and keep soil warm.
Place the trays in a location that receives gentle bottom heat. The top of appliances, such as water heaters, are ideal -- but you can use heating mats as well.
Check the trays daily for germination. Under ideal conditions, seeds often germinate within three to five days but may take a week or more.
Remove the plastic once the seeds germinate to allow for air circulation. Move the plants to an area that receives bright, indirect light.
Thin to the healthiest seedling when the tomato plants are 2 inches high and have their second set of true leaves. Clip the weakest plant at the base with a pair of scissors as pulling disturbs the roots of the remaining plant.
Plant two to three Tumbling Tom tomato seedlings per 12-inch pot and display in full sun once the danger of frost has passed and nighttime temperatures remain above 55 degrees Fahrenheit.