1. Get fresh seeds
Seeds that have been around for a while will have lower germination rates. It’s best to use seeds 4 years old or less; however, older seeds can be used if they have been stored in cool and dry conditions.
2. Get the right mix.
Buy some seed starting mix at the local garden store, Kmart, or Walmart. A good mix is a combination of peat moss, vermiculite, and perlite.
Before using the mix, combine with warm water, mix and allow to sit overnight. It should be damp not soaked or soggy.
3. Select some containers
Tomatoes will germinate in anything as long as the seeds get moisture and warmth.
You could use growing “flats” that you can buy in the garden department of many discount stores or at your local nursery or you could make your own out of plastic milk jugs or other similar containers. Make sure that the container has sufficient drainage.
Once the seeds have germinated and the first true leaves have appeared (usually approximately 30 days), the seedlings will be potted in larger containers (at least 3-4 inches in diameter.).
4. Plant your seeds
Fill your starting containers with damp seed starting mix. Plant your seeds about 1/8 inch (3 mm) deep and firm the mix gently to make sure the seeds are in direct contact with the moist mix.
You may wish to cover the containers with plastic to retain moisture. Allow for some air circulation but don’t let the seeds dry out, they will not germinate.
5. Be patient and wait for germination
Place the containers in a warm location out of direct sunlight, sunlight is not needed during the germination process and direct sunlight, although not harmful, will cause the seed starting mix to dry out.
The seeds will germinate within 5 to 10 days when kept in a temperature range of 70 to 80º F (21 to 27º C). Lower temperatures will delay germination, higher temperatures will speed germination. Temperatures below 50º F (10º C) or above 95º F (35º C) are detrimental to germination.
6. Put the seedlings under light
Put the seedlings under strong light as soon as the first seedlings emerge from the soil. If the seedlings don’t get sufficient light they will become spindly as they try to reach for the light. Fluorescent shop lights or grow lights are good alternatives unless you have a heated greenhouse.
If fluorescent lights are used the leaves must bee within inches of the bulbs. The lights should remain on for 16 to 18 hours per day.
7. Continue to monitor plants
Make sure the plants are in a warm location and continue to receive plenty of light. Water when the planting mix has almost dried out.
When the plants develop their first true leaves (about 30 days), they should be transplanted into individual 3 4 inch container.
8. Begin to move the plants outside
Once the night time temperatures remain at 55º F (13º C) and above, it’s time to start moving the plants outdoors in a process called hardening off. Place the plants in a sunny location and protect them from strong winds. Allow the plants to remain outside for longer and longer periods.
Once the garden soil has warmed up and the night time temperatures remain at 55º F (13º C), the tomato plants are ready to be planted in the garden.