Tomatoes are heat-loving plants that need a long season to grow from seed to fruit. In all but the most tropical U.S. climate zones, it's necessary to give them a head start by starting the seeds inside in very warm conditions and planting vigorous seedlings outside only when the weather has warmed up. This way the plants will have enough time to grow and ripen their fruit before the days shorten and weather cools at summer's end. Plan to start germinating your seeds about 6 weeks before the last frost date in your area so they'll be ready to plant about 2 weeks after that date. Ask a good local nursery, your local Co-op Extension Service, or best of all, an experienced local gardener, if you aren't sure when that date is. The goal is to have sturdy seedlings ready to plant into the garden at the time when spring weather is warm and settled and night temperatures are consistently in the 50 ° range. For example, if night temperatures are consistently in the 50 ° range at the end of April in your area, count back 8 weeks for the right date to start your seeds indoors, in this case at the end of February. It's important to use a good light, friable seed starting mixture for your plants, rather than ordinary garden soil, because garden soil may contain fungus organisms and often get adobe-hard after a few waterings. You should be able to find good quality seed starting mix at a well-stocked garden center (or you can send for the fine seed starting mix Shepherd's carries in the catalog). Planting containers or flats need to be at least three inches deep for roots to grow, and have small holes for drainage so those roots won't rot. You can use old 4-inch plastic plant pots, old yogurt or cottage cheese cartons, or half-gallon milk cartons cut lengthwise, all with drainage holes punched in the bottoms. Don't use old plastic "6-packs" as they do not have enough soil volume and dry out too quickly. Add water to soil mix and mix well; it should be as moist as a wrung-out sponge before you put it into your containers. Fill containers close to the top with evenly premoistened soil mix. Tap or jiggle the container to settle the mix. Write the variety names and sowing date with indelible markers on small labels and place in containers. Make seed furrows about 1/4 inch deep and drop in the individual tomato seeds about an inch apart. Cover with about 1/4 inch of soil mix and firm gently. Water the seeds to settle them in with a spray bottle or a very gentle spray nozzle. Your tomato seeds need warmth, 75-80 degrees, to begin the germination (sprouting) process. Light is not critical at this stage, but bottom heat or a warm location is. If you are using an electric seed propagation mat, just plug it in and put the seed containers on it. If not, put them on top of the water heater or refrigerator; anywhere they'll have gentle steady warmth. Keep seed flats or containers moist but not soggy, and expect germination within 10 days of sowing. Check at least once every day for signs of emergence. Just as soon as the seeds have begun to sprout and show above the soil line, the baby seedlings require bright light. Artificial fluorescent shop lights are a good way to provide light for seedlings; suspect them from chains with cup hooks, so the lights are an inch or two above the tops of plants. Move them up as seedlings grow, keeping them just 2 or 3 inches above the tops of the plants. If using a sunny windowsill, be sure to rotate plants and protect them at night, when windowsill temperatures can plummet. Give seedlings lots of light‹16 hours a day is fine. Plants that don't have enough light will grow up weak and pale, with long stems leaning toward the light. Seedlings can be grown on at temperature somewhat lower than those for germination (a range of 65 to 75 degrees). When your seedlings are up and growing, and have at least 2 sets of leaves, it's OK to let the top half-inch or so of soil have a chance to dry out between waterings. Check daily by putting your index finger into the soil‹actually using this finger test to see how moist soil is works best; it's hard to tell from just looking, even for experienced gardeners. "Potting Up" Your Tomato Seedlings When you seedlings have several sets of leaves, you need to move or "prick out" seedlings to a deeper flat or individual 4-inch pots. First, fill the new containers with moistened soil mix. Lift the tiny plants carefully with the help of a large fork, pushing all the way to the bottom of the container to get all of the roots; the less they are disturbed, the better. Lower each plant into the hold you've made and plant it deeper in its new home. Tomatoes (unlike other plants) will make new roots along their buried stems, so if your seedlings are leggy, you can transplant them so that their stems are covered by the soil up to the base of the topmost cluster of leaves. Gently firm the soil around the transplants and water carefully. About a week after pricking out, start feeding the plants each week with a good all-purpose liquid fertilizer such as Shepherd's Garden Seeds Vitalize (Sea Kelp & Fish Emulsion) or Miracle-Gro or Rapid-Gro, diluted half-strength. Planting into the Garden After about a month, the seedlings will begin to crowd each other and the weather should have warmed up enough to plant them outside. (Remember you will gain nothing by planting them out before night temperatures remain above 50 °. If spring stays chilly, transplanting them into larger pots is a good idea if you have room to keep them well-lighted and warm.) Plant out only the stockiest plants with healthy, well-developed root systems. Pick a sunny spot with well-drained soil that has been amended with ample organic matter. "Harden off" your seedlings over 4 to 6 days to get them used to outdoor conditions. Do this by putting them out in a protected shady spot for first a half day, then a full day, and then move them gradually into full sun. Try to transplant seedlings on an overcast day or in the late afternoon to minimize stress. Set tomato plants 3 feet apart and several inches deeper in the soil than they were in the container. Plants will form roots along the buried stem. Firm soil around the plants and water thoroughly but gently. Tall growing "indeterminate" varieties of tomatoes (meaning plants that will keep growing, blooming, and setting tomatoes throughout the season until frost kills them) need strong supports. Use sturdy stakes or make or buy wire tomato cages at least 5 feet tall and tie plants loosely with soft string or torn rags as they grow up. "Determinate" or busy tomatoes need only 2- to 3-food supports. Keep plants evenly moist but not soggy. Mulching with compost, dried manure, or other organic material is a good way to maintain an even moisture balance. Alternating wet and dry causes cracking and blossom end rot in ripe fruit.