Tomatoes may be the most often grown vegetable in American vegetable gardens. Tomatoes are extremely versatile; they can be enjoyed raw, steamed, baked, broiled, fried, in stews. Tomatoes can be grown in all hardiness zones so long as there is no frost, but certain varieties may be best suited to your particular area; check with nurseries for the best local varieties. When collecting seeds from tomatoes, make certain that they are not hybrid tomatoes, as these tomato seeds may not grow or may grow poorly. Obtain seeds from heirloom tomatoes whenever possible.
Buy or obtain from a friend a tomato of the variety you wish to grow. Ask your grocer if a tomato is a hybrid or not before purchasing. You can purchase many varieties of tomato seeds inexpensively from nurseries, home centers, even many hardware stores and supermarkets.
Cut your tomatoes in half and scoop or squeeze the seeds and some pulp into a bowl. Place a damp paper towel over the bowl and set the bowl aside in a dark and warm location (such as inside a cupboard) for 3 to 4 days, until a layer of mold develops on the seeds. This is fermentation and kills many bacteria that can affect tomato seeds.
Place the fermented seeds in another bowl and fill with water until you have an equal amount of water and seed material. Stir the seeds and pulp vigorously and then pour off the water. Repeat the process until you have only clean seeds left. Bad seeds float to the top during the washing process and should be discarded; good seeds stay on the bottom.
Spread the seeds on a ceramic plate to dry. Stir the seeds occasionally as they are drying to prevent them from sticking to the plate.
Fill peat growing pots with a mixture of 1/3 peat moss, 1/3 vermiculite and 1/3 compost. Dampen well. Press the tomato seeds 1/4 inch into the soil mixture, planting seeds approximately 1 inch apart. Cover seeds with 1/4 inch of the soil mixture, leaving it loose.
Place the growing pots in a well lit and warm area, approximately 70 degrees Fahrenheit. Use a spray bottle to keep the soil damp but not soggy.
Wait for seeds to germinate within 7 to 10 days. Allow the plants to get several hours of direct sunlight each day once they have germinated, keeping them in a sunny window so they stay warm.
Transplant outdoors after all possibility of frost has passed and once plants have at least 3 leaves and are at least 2 inches tall. Plant your tomatoes at least 3 feet apart in soil that is a 50/50 mix of garden soil and compost. Keep soil moist but not soggy.