I learned that to grow tomatoes from seeds, you need to do these 5 things ...
1. Start your seeds in fresh, moist dirt and sterilized containers. Apparently we did only half of this ... we used disposable plastic cups and took a risk by reusing our dirt from last year.
2. Tomato seeds need heat, not light, to germinate. You have to plant your seeds about 1/4 inch deep and make sure you provide a consistently warm environment of at least 70-80°F. To do this, we bought heating mats. Heating mats are expensive, but it was totally worth it when our seeds sprouted in 2-3 days. We wish we had not waited for an entire month to do this!
3. Seedlings need plenty of light. When your seeds sprout, you need to move them to a place where they can get plenty of light for at least 12 hours a day. If you live in Indiana, you know it's not likely we have that much sun this early in spring. So we rigged a simple setup with plant light bulbs and some cheap clamp lights.
4. When you see the first set of true leaves, it's time to thin out or transplant your "babies" into individual containers. This will also be a good time to fertilize your plants. And if you want to, start brushing the top of your seedlings daily. This action is believed to help your plants grow sturdy and stocky (as opposed to tall and spindly).
5. Tomato plants are ready to be planted outside when the night temperatures are consistently in the upper 50s. When you move them to their final space, make sure you plant your tomato plants deeply. This will help ensure your new plants are well-rooted and grow strong all season long.