If you live in a cooler climate, you may want to start germinating your tomato seeds indoors. Doing this will ensure your plants will produce fruit before the fall frosts start. You should begin indoor germination in March so the seedlings will be ready for transplant by May. Tomato plants are sensitive to frost, so err on the side of caution when deciding when to put your seedlings in the ground.
Fill seedling trays 3/4 full with either peat or perlite. Seedlings do not yet need the nutrients found in soil. However, if you wish to use a potting soil, you may do so.
Sow one tomato seed per cell in seedling trays. Seeds should be placed 1/4 to 3/8 inches deep.
Cover the seedling trays with the lid they came with. If your trays did not come with lids, you may cover them with a piece of clear plastic. This will help hold in warmth and moisture.
Water the tomato seeds once or twice a day. Do not let the soil dry out; it should remain moist, but not overly wet, at all times.
Place seed trays in a sunny spot in your house. If the seedlings will be staying indoors for any length of time before being transplanted outside, you may consider buying a plant light at your local hardware store. Tomato plants should receive approximately 14 hours of light per day.
Remove the lid or clear plastic after your tomato seeds have germinated to prevent growth restriction.
Transplant the tomato seedlings into potting soil a few weeks after germination. Do not use any fertilizer until the seedlings are in the ground outside.