Growing Tomatoes from Seeds

Cherry Tomatoes on a Vine
Cherry Tomatoes on a Vine.

Gifted kids love to learn about how things work - and that includes learning how plants grow. Teaching them how to grow plants from seeds is a great way to help them learn about plant growth. An easy plant to start with is the cherry tomato, which comes in many varieties. Plan to plant the seeds six to eight weeks before the last frost is expected where you live. (Check U.S. normal weather on the Golden Gate Weather Services Web site.) However, if you live in a frost-free zone, plant the seeds six to eight weeks before the temperature at night falls regularly in the 50s.


  1. Prepare the pots
    Fill the small pots close to the top with the seed-starting soil or potting soil. Pat the soil down a little so that it is not too lose, but isn't packed tightly. Have the kids poke a hole about 1/4" deep in each of the containers. To make it easy for them, show them a spot on their fingers that should not go below the dirt. Depending on their age and finger size, it could be the end of the fingernail (at the cuticle) or perhaps at the first finger joint. This way they don't have to guess at the depth.
  2. Plant the seeds
    Make sure the seeds aren't sticking together and then have the kids put two or three seeds in each hole. Some seeds may not germinate, so it helps to have more than one seed in each pot. Cover the seeds with about 1/4" of soil. To help the kids know how much soil to use, do the first one yourself (or do it ahead of time). Use a measuring spoon and then determine how many times the spoon must be filled for the seeds to be covered by 1/4" of soil. That way you can tell the kids to put X number of spoonfuls of soil in the pots. Then pat the soil.
  1. Care for the seeds
    Water the plants just enough to make the soil moist. Place them in a spot where they can get strong sunlight all day. An east window is best, but it should also be in a relatively warm place (about 75 degrees Fahrenheit). If you don't have a good location for sunlight, then place a grow light or strong fluorescent light over the plants. The plants should be watered every day or every other day, just enough to keep the soil moist. If the soil feels moist, the plants should not be watered.
  1. Watch the seeds grow and remove extra sprouts
    This can be an exciting time for the kids. They might enjoy keeping a journal of what they see each day. They can include the date and time of their journal entry, along with the description of what they see. When does the first sprout appear? What does it look like? If they like to draw, they can also draw what they see, or they can take pictures to go with their descriptions. After about a week, if any pot has more than one sprout, the kids should pull out the smallest ones.
  2. Prepare the plants to go outside
    As odd as it might sound, plants grown from seeds indoors need to get used to being outside. This is called "hardening." Begin this process when there is no longer any danger of a frost. At this point, the plants should be somewhere between 4" and 6" high. To harden the plants, take them outside during the day and then bring them in for the night.
  3. Select and prepare an area for transplanting the plants
    Pick a nice sunny location. Have the kids dig holes about two to three feet apart with the spade. The holes should be wide enough for the peat pots to fit. They should be just deep enough so that the top of the pots are just below the dirt or the first leaves are just above the dirt. If you aren't using peat pots, the holes may not need to be so wide, but it won't hurt if the holes are too big. Too big is better than too small! Add some plant food to the hole, but not too much since adding too much can kill the plants. (Follow the directions for the plant food.)
  1. Transfer the plants to the outdoor location
    If you are using peat pots, this is easy. All the kids need to do is put the entire pot into the hole. However, if you used some non-biodegradable container to grow the seeds, the kids will need to remove the plants. The plants will need to be removed from the containers and placed into the holes. This must be done carefully so that the roots aren't damaged. Rather than pull the plants out by the stem, it's better to "pry" them out with a fork. After the plant is put into the hole, fill any spaces with soil. Then pat the soil down so that the plant is not falling over.
  1. Water the plants and continue to care for them
    Once the plants are all firmly planted into the ground, have the kids water them. Have them use a watering can rather than a hose since they don't want to flood the plants. However, the kids need to provide enough water so that the it reaches the roots. Each day, the kids should go out and check the soil to make sure it is moist, but if the plants are properly watered, they will only need to be watered about once a day. If the ground is already moist, for example after a rain, they will not need to be watered.
  2. Watch the plants grow and harvest the fruit!
    Yes, tomatoes are actually a fruit. As the plants grow, you may want to buy or make supports for them. Cherry tomatoes are great for the kids because they are sweeter than regular tomatoes. They make wonderful and healthful snacks for the kids all summer long.


  1. The pots for the plants should have a small hole in the bottom. This way if the kids put too much water in the pots, the water will drain and the plants won't drown. You can find small, very inexpensive peat pots, which are great to use since when it's time to plant the seedlings outside, the kids can plant the entire pot and won't have to worry about damaging the roots. They will have to dig slightly larger holes, but it's a great option for beginners who aren't sure how to handle seedlings.
  2. If the plants are watered too much or too little, they will not thrive. If they do not get enough sunlight, they will become spindly. If the sprouts turn black or stop growing, chances are they are being watered too much. If they turn yellow and look dry, they are not being watered enough. If they get spindly, they are not getting enough sunlight. The plants and the soil need to be checked every day.
  3. When plants are watered, it is best to water the soil rather than sprinkle water over the plant itself. It won't hurt the plant if water gets on it sometimes - after all, plants do survive rainfall outdoors. However, it's the roots that need the water, not the leaves. Also, since it's the roots that need the water, it is best to water "deep" and less often rather than frequent surface sprinkling.
  4. If you can, also pick at least one sunny spot close to the house. The house will provide some warmth so that the plant produces tomatoes a little longer than the plants away from the house.
  5. Have the kids continue their growing journal throughout the summer, or at least until the plants bear fruit. They can measure the height of the plants, when the plants start blossoming and when the fruits first appear. If you have enough plants, you can even encourage the kids to conduct an experiment. One plant can be watered less than the others (but not allowed to die) and one can not get plant food. These plants should be labeled so they aren't mixed up and then the kids can keep track of any differences in growth and fruit production.

What You Need:

  • Small pots or planters
  • Seed starting soil or potting soil
  • Cherry tomato seeds
  • Small watering can
  • Grow light or strong flourescent light (optional - see step 3)
  • Hand spade
  • Plant food

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