How to Grow Tomatoes from Seeds

Do you want to grow a tomato plant (literally) from the ground up? Using just the healthy, ripe tomatoes you probably already have sitting in your fruit bowl, you can grow several unique tomato plants in your garden. Study the process below to learn how to grow a tomato plant from seed, whether you choose to buy pre-packaged seeds or ferment your own.

Choosing Your Method

1. Buy seeds from a reputable source. You can buy seeds online at seed exchange sites, from your local nursery, or from other gardeners.

2. Dry your own seeds from a ripe tomato. You can actually squeeze the seeds from a ripe tomato and grow seedlings from them. Refer to section two, "Fermenting Your Own Seeds," below for instructions on how to prepare wet seeds for planting.

3. Choose a variety. There are over one thousand different varieties of tomato plants available. They can mostly be classified into three categories that can help you decide which variety to plant in your garden.

- Heirloom or Hybrid: Heirlooms are tomatoes that have been genetically reproduced for several generations without any cross-breeding. Essentially, they're pure-bred tomatoes. Hybrid tomatoes are a cross between two varieties.

- Determinate or Indeterminate: This method of classification describes the length of time for which a plant produces fruit. Determinate plants produce for a few weeks, while indeterminate plants produce fruit throughout an entire growing season until climate conditions become too cold.

- Shape: Tomatoes are also classified into four categories of shape: globe, beefsteak, paste, and cherry. Globe is the most popular shape, beefsteak is the largest, paste tomatoes are used to make sauces, and cherry tomatoes are small, bite-sized tomatoes often used in salads.[1]

Fermenting Your Own Seeds

1. Choose tomatoes from a healthy plant. Make sure your tomatoes are from a plant that was grown from an heirloom or open pollinated seed. If you choose tomatoes from a hybrid, or a plant with chemically-treated seeds, the results may not be as impressive.

2. Cut your tomatoes in half and scoop out the insides into a plastic container. You will want a container with a loose-fitting lid as the tomato pulp and seeds will be sitting in the container for a few days. A layer of mold will develop on the seeds. This process can destroy many seed-borne diseases that could affect the next generation of plants.

3. Label your container. If you are fermenting several different types of seeds, be sure to label the container with the correct variety to avoid any mix-ups. Set the lid on top of the container but do not seal it to allow oxygen to reach the pulp.

4. Set the pulp in a warm place out of direct sunlight. The fermenting process isn't pretty, or pleasant to the nose, so set the container out of the way somewhere to avoid contact with the mixture.

5. Stir the container daily until a layer of white mold forms on the surface. It usually takes about 2-3 days for the mold to form. Be sure to harvest the seeds shortly after the mold forms so that the seeds do not germinate in the container.

6. Harvest the seeds. Wearing gloves, scoop off the moldy layer. The seeds will have sunken to the bottom of the container.

7. Pour water into the container to dilute the mixture. Let the seeds settle at the bottom and continue to pour off the unwanted parts of the solution. Be careful not to throw away the seeds.

8. Catch the seeds with a strainer and rinse them thoroughly.

9. Spread the seeds over a non-stick surface and allow them to dry for several days. A glass or ceramic flat dish, baking sheet, a piece of plywood or a window screen all work well. It can be very difficult to remove dried seeds from paper or cloth. When they are dry, you can package them in a sealed plastic bag until you are ready to plant them. Be sure to label the variety of seeds on the package.

10. Store the seeds in a cool, dark place. You can also place them in an airtight container in your refrigerator to simulate a winter climate. Do not place the seeds in the freezer, doing so will damage them.

Planting Your Seeds

1. Start tomato plants from seeds indoors 6 to 8 weeks before your last frost. To prepare your tomato plants to be transferred outdoors, start your seedlings indoors while it is still cold outside. Cool temperatures in early spring can stunt growth or even kill young seedlings. Start your seedlings indoors to improve your production chances.

2. Purchase plastic peat pots or similar small pots for growing seedlings. You can find these pots at your local nursery or garden supply store.

3. Fill your peat pot with the soil mix of your choice. For example, one mix could be made using 1/3 peat moss, 1/3 coarse vermiculite, and 1/3 compost.

4. Sow 2 to 3 seeds 1/4-inch deep in soil in each pot. Cover with soil and pat down lightly.

5. Store the containers in room of 70 to 80 degrees Fahrenheit until germination occurs. When the seeds germinate, move them into full sun or under grow lights.

6. Mist the seeds daily for the first 7 to 10 days. When you start to see sprouts, you can water less frequently. More plants are killed by too much water (that rots the roots) than too little water so water sparingly after the plants sprout.

7. Check your pots every day. Once the plants peek out of the soil, they will grow pretty fast.[3]

Transferring Your Plants

1. Notice if your plants have grown to at least 6 inches high. When there is no danger of frost outdoors and your plant meets the height requirement, they are ready to be transferred outdoors.

2. Harden off your plants. About a week before you plan to transfer your plants outdoors, you need to gradually adjust them to outdoor temperatures. Gradually expose the plants to the sun, starting in a partially shaded area and slowly extend the number of hours the plants stay outside each day.[4]

3. Prepare your garden space. You want to use well-drained soil with a good amount of organic matter present.

- Consider mixing peat moss into the soil to improve drainage. While peat moss can absorb and hold 10 to 20 times its dry weight in water, it is considered harmful to the environment and is relatively expensive to buy. There are several environmental costs associated with the peat moss market, including the fuels required to dig drainage ditches, harrow and dry the peat, bale it, and ship it long distances.[5]

- However, if you want to use peat moss anyway, remove no more than half of the soil and mix the removed soil with an equal ratio of peat moss. Mix the peat moss/soil mixture back into the planting area.

- If you are concerned about the possible effects of peat moss, consider building a raised garden out of wood instead. Make a simple raised garden box out of two 1 x 8-inch cedar boards, which come in 8-foot lengths. Cedar is a good choice for a garden bed because it won't rot with age.[6]

4. Test the pH level of the soil. Tomatoes grow best when planted in soil with a pH between 6 and 7.

- Your local agricultural extension office should have soil testing forms, bags and instructions available. After making adjustments to the soil, test its pH level again.

- If the pH level is below 6, add dolomite lime to the soil to raise the pH level.

- If the soil pH is above 7, mix in granular sulfur to lower the pH level.

5. Dig a hole about 2 feet deep. It needs to be deep enough that you can plant your seedlings and only the top 1/4 of the plant will be sticking out of the ground. Place a scoop of organic matter such as compost into the bottom of the hole. This will give your plant an extra boost, and also help keep the plant from going into shock from transplanting.

6. Carefully take the plants out of their pots and place them in the ground. Try not to disturb the roots during the transplanting process. Set the transplants deep enough so that the soil touches the first set of new leaves when you cover the plant with soil. Pat the planted area lightly.

7. Fertilize with fishmeal, chicken manure, or a premixed low-nitrogen, high-phosphorus organic fertilizer and water thoroughly. You will need to repeat the fertilizing process each year.

8. Place stakes or trellises next to the plants. This will give the plants a support to latch onto as they grow and makes it easier to pick the fruit from the vines. Be careful not to disturb the roots.

Growing Your Plants

1. Feed and water your plants often. Water at the base of the plant to avoid developing mildew on the leaves. Sprinkle your plants with liquid seaweed and compost weekly to increase fruit production.[7]

2. Pluck suckers off of your plants. If you want to promote better growth and a higher fruit yield, pluck the suckers off of your tomato plant using your fingers when they appear. Suckers are the small stems that grow off of the main stem. Leave a few near the top of the plant to avoid sunscald.

3. Harvest the fruit at its peak. Fruit should appear about 60 days after transplanting. Check the plants daily once they begin to ripen to ensure peak flavor. Gently twist the fruits and avoid pulling at the vine.