Tomato is an annual vegetable plant capable of producing fruit up to the first frost. Tomatoes need heat and sun to mature. There are varieties of tomatoes with shorter growing periods to meet the climate restraints of northern states, like those USDA zones 3 and 4 that have short summers. The small, Sub-Arctic Plenty variety needs only 45 days to mature while large tomato varieties like Supersteak can take more than 80 days to mature. The best way to start tomato seeds is indoors in any climate.
Prepare seed pots about six weeks before the last predicted frost date or according to the directions on the seed packet. Seed pots may be empty plastic containers like small yogurt cups or pre-packaged seed pot kits may be used. If using plastic containers, punch drain holes in the bottom using a knife and fill the container with clean potting mix.
Place the soil-filled container on a tray to collect water overflow. The seed kit may come with a built-in tray. Moisten the potting medium in the seed pots.
Push one to two seeds into each seed pot just far enough to cover the seed.
Cover the pots.Kits will come with a plastic lid to cover the seed pots. For plastic containers like yogurt cups, place a sandwich bag over the container and secure it with a rubber band to help hold in moisture.
Place the container in a sunny location, usually a south or west window. If using a grow lamp instead of placing by a window, position the lamp about 6 inches over the container.
Keep the potting mixture moist. Moisture can be added by lifting the cover and spritzing or gently drizzling water onto the soil.
Remove the plastic cover at about five weeks.
Plant outdoors after the last predicted frost. Till the soil to at least 8 inches. Create an opening in the soil for seedling using your fingers. Place the seedling in the ground with the lowest leaves below ground level. Additional roots will form, adding to the stability and health of the plant.