How to Plant, Grow, and Save Seeds from Tomato (Solanum lycopersicum)

As well as having the distinction of being America's favorite garden vegetable, tomatoes are a great crop for the beginning seed saver. Tomato plants can either be determinate or indeterminate. Determinate plants will produce tomatoes that all ripen around the same time. Indeterminate plants will continue putting on new growth and new fruits throughout the growing season.


Tomato plants are regularly started indoors 6-8 weeks before the last spring frost and transplanted outdoors when soils have warmed. Plant tomato seeds ¼” deep into small containers of potting soil. Seeds will germinate in 1-2 weeks.

Transplant tomato seedlings outdoors in a sunny spot as soon as the soil has warmed and after all danger of frost has passed. Most varieties require ample space to grow, so space your plants 24-48” apart in rows at least 36” apart.

Tomato plants are susceptible to early blight, blossom end rot, late blight, Tomato Mosaic Virus, and many other diseases. Both indeterminate and determinate tomato varieties typically require trellising, staking, or caging to keep the tomato vines off the ground, where they are more susceptible to these diseases. Prevent soil-borne diseases by rotating crops and by removing diseased plants from the garden.

Eating and Storing

Tomatoes come in all shapes, sizes, and colors. Harvest tomatoes when they are firm to the touch but seem to give a little. Ripe fruits will pull easily from the vine.

Store tomatoes at room temperature or in the refrigerator. Fruits will continue to ripen after being picked if they are stored in a warm place.

Enjoy tomatoes at peak ripeness sliced into a BLT or mixed together into a cucumber salad or fresh salsa. If you are lucky to have a bumper crop of tomatoes, try making your own tomato soup, tomato paste, or homemade pasta sauce. Blanched and cored whole tomatoes can also be frozen or canned.

Saving Seeds

Tomato is an annual crop. It will complete its full life cycle, including germination, reproduction, and death, in one growing season.

When saving seeds from tomato, separate varieties by 10-50 feet. A single tomato plant can produce viable seed. To maintain a variety over time, save seeds from between 5-10 plants.

Tomato seeds are mature when the fruit is ready to eat. To save seeds from tomatoes, squeeze the pulp and seeds out from the inside of the fruit into a container. Leave this container to sit for at least one day in a warm (80 to 90 ℉) spot out of direct sunlight so that the pulp can ferment. This process allows the tomato seeds to separate from the gelatinous coating that covers them. Viable seed will sink to the bottom of this mixture and dead seeds will float. When a small amount of mold begins to form on the mixture, pour off the floating solids and dead seeds and thoroughly rinse the sunken seeds in running water. A fine mesh strainer is ideal for this step of the process. Once thoroughly cleaned, seeds can be placed on a screen or a coffee filter and left to dry for 5-7 days. When stored in a cool, dry place, tomato seeds will remain viable for 5-10 years.

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