Tomatoes are thought to be from Central and South America but their exact origins are unknown.  Spanish conquistador Hernan Cortes brought seeds from plants found in an Aztec city to Europe where they immigrated to America as well as many other countries including Asia. They are very popular in Mexico and other latin countries as an ingredient in many dishes. Before the civil war, tomatoes were considered an ornamental plant. In fact, they were believed to be poisonous and children were warned not to eat them. Back then it was commonly thought that “if the cattle wouldn’t eat it, neither should you”.  This was due to the fact that the tomato plants are in the family of Solanaceae, also called “Nightshade” which is known to be poisonous.

Although they are used mainly as a vegetable in many dishes and preparations, tomatoes are actually a fruit. They were referred to as “love apples” at one time.


Having the skills to grow tomato plants in your own garden is a sign of self-sufficiency and brings with it a sense of security and pride in your own accomplishments. Many people these days live in mobile homes, apartments or places where they have very little land, if any at all, to make a garden space and that is why container gardening is so popular. Even a beginner can grow tomatoes indoors with just a few simple tools and instructions. If you have never gardened before, here are a list of 15 things that everyone should know before starting to grow tomatoes indoors.


1 Seasonal Crops

Tomatoes need warm weather and plenty of sunshine but did you know that it’s possible to grow tomato plants in the winter if they are being grown indoors. Many gardeners choose to start their tomato plants inside and then transfer them outside to be planted in the ground when they are matured.  LED grow lights provide heat and light during the winter season to mimic summer. There are different varieties of tomato plants  and many of them adapt easily to growing indoors.

Seeds or Plants?   Which is the best or the easiest method to grow tomato plants, seeds or starter plants? Really, it is only the difference of a few weeks and of course the price. It depends on whether or not you want to wait longer to see the sprouts and if your starting budget will be enough for plants instead of seeds. A packet of seeds will cost, on the average, a dollar or two at the most but a 6-inch plant is more like $5 to $6. So for ease of planting , it would be better to buy the starter plants. But if you really want to learn to do it all yourself and be able to replicate the process, start with a seed packet. The reason for this is, that once your plants have grown you will need to re-seed periodically to keep a steady supply of tomatoes.


2 What Type is Best Grown Indoors?

The next question is what kind of tomatoes grow best indoors? There are many varieties of tomatoes. You may be familiar with some of them by their names in the grocery store: heirloom, early girl, roma, beefsteak, sweet cherry tomatoes and tiny grape tomatoes just to name a few. Some produce small to medium-size fruit, while others produce larger fruit. The heirloom and beefsteak variety produce larger, firm skinned tomatoes. They all are good at growing indoors, but deciding which ones to grow depends on how much you plan to use. You could grow a few hanging baskets of roma or cherry tomatoes and have a few pots of the big heirloom tomatoes. Experiment and find the ones that work best in your situation and go from there.

3 Temperature

Optimally tomatoes grow best in hot humid climates. Places with long summers and warm temperatures are the best to grow tomato plants. Your indoor temperature will need to be between 65 and 75 degrees during daytime hours. Unless you live where it is really warm in the winter you will need to use grow lights to produce the same effect. There are several varieties of grow lights but LED lights tend to be the best for growing vegetables indoors.

Tomatoes need approximately 12 to 14 hours of full sun during the day but do not need it around-the-clock, so remember to turn your grow lights off sometimes to simulate night time because it is part of the growing process too. Tomatoes grow during sunlight and rest when the sun goes down. This resting phase is also important for growth.

4 Ventilation and Air Circulation

The place where you put your seeds to germinate will need to have good ventilation and air circulation. Having a small fan near an open window will allow good air flow through your growing space. There may be times when it gets too hot inside from using the grow lights. Turn on the fan and let it run until the temperature goes back down to the desired level. If it gets too hot your budding plants may die from too much heat similar to how they do outside in the sun.


5 LED Grow Lights

LED stands for Light-emitting Diode. This term refers to a device that emits light in the blue and red spectrum. It often appears as bright purple light. The LED lights produce the same results as other types of grow lights but emit less heat making them an economical tool for growing tomatoes indoors. Studies performed at the University of Florida using LED grow lights concluded that plants grown under this type of light produce tomatoes with a higher nutrient value than other types.

Why is light important for growing tomatoes? Plants derive energy from sunlight, as well as grow lights, and food and water. Without light, the plants wouldn’t grow very well. Absorbing energy from light, called photosynthesis, is what makes the leaves turn green and the plant to flower.    What are the benefits of using LED lights? Higher efficiency, lower power usage, and longevity. The bulbs can last 10 years or more which makes them very economical and they use less energy to use so they are a “green” solution as well for those who are eco-friendly. Typically, tomato plants require 12-16 hours of sunlight (or grow light) per day, and should sit about 6 inches or so above the seedlings. Remember you also have to simulate night time as part of the growing process, so remember to turn off your lights for a few hours in the evening.

Determine the bulb wattage by square foot here:


6 Potting Soil

When it comes to planting, not just any type of dirt will do. You will need a high-quality potting soil mix to plant your seeds. High-quality potting soil will have ingredients such as peat moss, vermiculite, and lime as well as aged bark.  Two examples of high-quality potting soil are Miracle-Gro and Roots Organic Potting Soil. The soil you use to grow tomato plants needs to have good drainage.  The soil should hold just enough water to allow the plants to absorb it by the roots without flooding. The top should feel slightly damp when touched with a finger. The Miracle-Gro formula will also feed your plants in the early stages giving them nutrients. These nutrients will eventually be depleted by watering but you can add small amounts of fertilizer or feed to your plants as they continue growing.  One way to test your potting soil for water density is to put some in a container  and add a small amount of water and see how quickly it drains out. It should drain within 5 to 10 seconds. This is how you know you have a good product.

7 Fertilizer

Fertilizer is basically another word for plant food. Miracle Gro is a very well-known plant food that helps plants grow to their maximum height.  When plants are in their growing phase they will require more frequent watering and a little plant food to keep them growing good. Plants use up a lot of energy growing and need to replenish their energy. An easy way to feed plants is to mix a little bit of plant food in with the water. You can do this once every two weeks or so for optimum health. Not too frequently though or it will throw off the nutrient balance between phosphorous and nitrogen.

8 Water

Since you do not intend to grow tomato plants outdoors you will not need access to a large amount of water. Plants need plenty of water and sunshine (or light) to grow healthy, but you can over-water which can kill your growing plants. To grow tomato plants outside you would typically use an irrigation method such as a drip hose or sprinkler, but plants grown inside do not require as much water. The basic method of watering seedlings is to fill a shallow tray with your containers, making sure to have drainage holes in the bottom, and add water until it just slightly comes up over the bottom of the containers. The plants will water themselves by soaking up the water from the bottom of the containers. Let them soak up the water for about 20 minutes and then pour out the remaining water. This will give the plants the exact amount of water they need without being too much. You can tell when plants have been over-watered because the stalks and leaves go limp and turn brown.

9 Containers

The containment method you choose to grow tomato plants in can vary by size and type. Seedlings are best started in small cups or even egg cartons because they only require a small amount of soil and take up very little room. As the seeds begin to sprout and grow, about 2-4 weeks later and again when they are 8 to 10 inches tall, you will need to transplant them into larger containers. You’ll want to be very careful separating the plant’s root systems when transplanting. You don’t want to do this very often due to the fact that the plants go through a little “root shock” being transplanted.

To grow tomato plants indoors you will need:

  • pots-ceramic, clay, etc.
  • tomato cages or tee-pee-style frame
  • hanging baskets
  • window boxes

10 Tomato Plant Growth Stages

There are 4 stages in the growth cycle of the tomato plant. These stages are germination, vegetation, fertilization and fruit. After the seed has been planted about a week or so it will begin to sprout.  The vegetation stage is when the leaves begin to multiply. The plant in this stage is focused on increasing its size and mass. In temperatures of 70 to 75 degrees, the plant will grow very quickly, doubling its size. It uses a lot of its energy during the growth phase. Fertilization begins when the plant has begun to flower. Tomatoes are self-pollinating and have both female and male sex organs. This is why you do not need to have them outside to be pollinated by bees. The fruit stage is after the flowers bloom and fall off and small fruit begins to show.

After the first tomatoes are harvested you can plant more seeds if you haven’t already done so. It just depends on how much you need as to how soon you want to plant more seeds. To grow tomato plants that produce the most tomatoes you need a steady supply of seeds. The amount of tomatoes produced by each plant varies. Small tomatoes like cherry and romas may yield 10 to 15 per plant , while larger varieties will produce smaller numbers.

11 Transplanting

Transplanting is the term used when you transfer the seedling from the seed pots to a larger container. When you plant the seeds the first time, you will place two to three seeds in each seed pot. This is to ensure that all the seeds produce because you may have a couple that won’t sprout. Once the seeds have sprouted and are a few inches tall you will replant them again, being careful to separate the plant’s root systems, and place them in individual containers. Each time you transplant be sure to remove a few leaves from the very bottom of the stem  (called pruning) before placing in the soil. You will have one plant per container and will transplant them one more time when they are about 6 inches tall. At this time they should be planted in a container or pot large enough to accommodate their full growth.

12 Supporting Plants

As your tomato plants begin to grow tall the stem will need to be supported by some kind of brace to keep it from leaning over and breaking. If the stem breaks the plant cannot get enough water and will start to die. Clean wooden popsicle sticks, small wooden stakes, pencil, or sticks will work to help grow tomato plants. As the plants grow larger and require more support, you can train them to wrap or vine around a tomato cage or structure like a trellis or teepee frame.

13 Grow Space-up not out

If you happen to have a patio space that you would like to use as your garden you can plant your tomatoes in ways that take us less space. Hanging baskets can be placed with a hook on patio overhangs and stacking window boxes on an open metal shelving unit can help your garden look as attractive as it is functional. There are tons of creative ideas for planters on Pinterest.


14 Harvesting and Saving Seeds

Once the plants have produced their fruit and have been harvested, you can extract and clean the seeds to be used for the next planting. After cutting open a tomato simply scoop out the seeds with a spoon and rinse them off. Lay them on a paper towel to dry before placing in a Ziploc baggie or paper envelope. Be sure the seeds are completely dry before putting them in the envelope.

15 Conclusion

By now you are more familiar with some of the terms and processes necessary to grow tomato plants and should feel confident in starting your seeds. If you follow the above tips you will have a hearty batch of tomato plants and will avoid many of the problems that beginning gardeners often face when starting out.