How to Grow Tomatoes Indoors with Lights- Step by Step Guide

(Last Updated On: January 1, 2021)

As mentioned in the University of Georgia’s publication on “Commercial Tomato Production”, more than 14 million tons of tomatoes are produced each year alone in the United States. To add more, globally the importance of this fruit is increasing 3% on average yearly.

Tomatoes are a massive source of vitamin c, antioxidants, potassium, vitamin k, and a few more nutrients. It immensely protects us from heart diseases, skin problems, cancer, and other critical conditions.

According to the facts, tomatoes do not re-grow. Hence, if the manufacturing of tomatoes does not rise proportionally, sooner we will have a shortage of tomatoes for every meal.

In this situation, you’ll be delighted to know, you can grow tomatoes indoors with light. That too, within a few months and limited efforts.

So why worry about the market’s contradiction when you have your own tomato garden. Who knows, perhaps you end up building a successful business with the yielding skill.

Let’s explore more about it.

Pattern of Growth

Tomatoes follow 2 types of growing patterns. Both of them have an excellent extent of advantage and a few disadvantages.

Let’s find out which one is beneficial for the average growers:

Determinate (Bush)

The determinate variety of tomatoes maintain an exact height more likely (2-4 feet). After reaching that much, these tomatoes stop their growth and mature the fruit.

With this, determinate tomato’s life ends here.

If you have a business or another reason to gather all the fruit at once, then determinate variety will be perfect for you.

You can identify determinate types by looking at the plant’s leaves as they stay closer to the stem and make the plant look bushier.


Indeterminate variety keeps growing throughout the whole season. It can reach a length of (6-20 feet), and so pruning would be needed. Unlike determinate, it continues to generate fruits till any harsh weather interrupts its survival.

By growing an indeterminate variety, you can enjoy fresh tomatoes the whole season and store them for the future. It is profitable for anyone who intends to have organic tomatoes at low costing with various other benefits.

To identify the indeterminate variety, check if the leaves have more space around each other. It has a similar outlook as the vines.

Growth Schedule

You might wonder, like a real tomato lover, “If I sow the seeds today, when will I finally have the edible version”?

Well, here to provide an approximate schedule of tomatoes growth:

The germination of seedlings requires 5 to 10 days in a favorable environment. You can transplant it into a container or anywhere indoor where you plan to grow it further.

As you go on, the ultimate fruiting phase would start around the 65th to 70th day. Soon you will know by seeing their color and texture.

A ripen tomato will be softer than the one at the prior stage. Then you are all set to collect and store the tomatoes.

A Closer Look to the Subsidiary Elements

While growing up tomatoes, these following conditions need to stay under supervision every single day. We’ll discuss the steps of planting later.

Before that, just so you know, planting it in the last container would take around 1-2 weeks, and the final fruiting would take 60-80 days.

Wherein, constant check on these following elements, from the beginning of their existence, assure your tomatoes successful growth.

A Normative Place

Tomatoes are mainly an outdoor plant. While growing it indoors, the location needs to be dedicating almost everything that an outer garden can offer.

It requires soil, warmth, and sunlight; the more, the better. Because more soil confirms enough nourishments and longer duration of available light keeps the thriving phase going all along.

Besides that, whatever indoor place you intend to use, make sure to have proper water drainage. Hence, the water won’t accumulate at one portion and cause overwatering.

Keep these things in mind before choosing the final location.

Additionally, it would be better if that space had any window which supplies a few hours of sunlight every day.

Light Assertion

Several companies are offering artificial grow lights with fascinating features. Most of them claim to accomplish all your needs.

Moreover, finding out the best grow light for growing tomatoes should be the ultimate motto.

From my point of view, initiating with the best led grow lights for high yield holds the highest convenience for you. As LED grow light has an excellent wavelength that covers all the needed spectrums so it becomes a solution for all stages of a tomato’s life cycle.

Even if you are just a novice in gardening, installing and running a LED light would be less challenging for you than other grow lights.

When the tomato seeds are in the thriving stage, it requires 14-18 hours of light.

At this stage, it doesn’t ask for any night-cycle, and so no routine darkness is essential.

Later on, at the beginning of the fruiting stage, you can decrease the duration of light and keep it for 8-12 hours nearly.

Lastly, the light is gravely connected with the temperature. We’ll discuss it thoroughly in the coming section to help you set the compatible atmosphere for the plant’s growth.

Required Temperature

As a matter of fact, tomato plants from germination to fruition urge for a warm atmosphere around.

But when you are growing it indoors with artificial light, you have no reason to panic for a warmer season outside since you can adjust the accurate temperature without nature’s help.

Concerning that, by setting the LED light at the right distance according to the intensity, you must manage the temperature of 70-75 degrees while at the seedlings stage.

Subsequently, 75-82 degrees at the fruiting stage and 65-75 degrees while they are in pollination.

Try to maintain a temperature around 75 degrees on average if only you have unavoidable obstacles in changing the temperature repeatedly during the growth. It will work for both phases.

While determining the temperature in your space for tomatoes, let not any fan or AC reduce the efficiency of adjusted temperature by cold air.

Suitable Pot or Container

While focusing on indoor planting, you can either plant the seeds in a cube-shaped planting tray or a large-sized container.

I prefer Greenfingers Seed Tray for germinating since this organic setup does not harm the delicate seeds.

However, place the seeds on each cube full of ¾ by soil and lightly cover it ensuring the soil is moist.

Now, wait at least 1-2 weeks. In the meantime, the seeds will sprout and,

  1. Reach 3 inches or more
  2. Start to grow green leaves

The whole time you can wrap the box with plastic or foil papers to ensure the required warmth. And then, this is the perfect time to transplant it in a 3-5 gallons container.

Afterward, the container with more soil, mixed with fertilizer, will strengthen the rooting and keep developing the plant silently.

Hydroponic or Soil Texture

Once again, you have 2 different options. You can either grow your tomatoes in a hydroponic mixture or move forward with soil – the most common and natural way.

As the researchers recommend, the hydroponic system provides a significant amount of nutrients through water. It helps the plant grow more efficiently.

People often question its taste as these tomatoes do not always taste natural. However, it has arranged all the elements and also committed to present healthy fruits.

Conversely, the soil is blessed with natural nutrition. I would recommend the newcomers avoid jumping into the hydroponic system before gathering much knowledge about it.

Otherwise, choose soil over the hydroponic system to avoid risks. But of course, you need to ensure if the soil’s texture, PH level, and other ingredients will get along with the tomato plants or not.

Adequate Watering

Showering your plant with the appropriate quantity of water is another vital task to follow consistently. Both overwatering and under-watering could harm the tomato plant at any stage.

Tomatoes specifically urges for more water than other similar kinds of greeneries.

That is why we already asked you to have a sound drainage system at your growing place. In that case, the water won’t accumulate; instead, it would maintain the accurate humidity.

Thinking of how much water does it require daily?

Well, a mixture meter would be useful to make an instant decision. Otherwise, you can simply penetrate your finger in the soil around the roots and observe if it is dry enough.

How to Grow Tomatoes Indoors with Lights

Finally, the moment has arrived. Without wasting any more time, roll up your sleeves, and follow the guidance to reach closer to your goals.

Step-1. Find an Ideal Place

Find a place with the mentioned requirements earlier where you will have sufficient soil and sunlight with a proper water drainage system.

Step-2. Select Tomato Seeds

You can do a little research and find a lot of different seedlings for tomatoes. If you like any particular heirloom, don’t be afraid to experiment with it.

Some of the most common names are Early Girl, Cherokee Purple, Yellow Pear, Big Boy, Juliet, Big Beef, Jersey, etc.

Step-3. Engage Grow Lights

The plant’s growth highly depends on grow light as tomatoes demand an enormous amount of light and heat to continue growing.

The reason why I put forward a full-spectrum King Plus LED Grow Light as it reduces your stress over different grow lights on various phases.

Step-4. Settle the Seeds Primarily

Plant the seedlings in a seed starter tray. Follow the previously given instruction on a suitable pot or container.

Step-5. Move the Seedlings after Germination

As you see, a few green leaves and a length of 3-5 inch predicts the end of germination. That is when you know it is ready to transplant on a larger container.

Step-6. Support the Extended Plant

Tomato plants do not have the strength to grow and stand upward like most of the other plants as it has a weak stem. If not support it with a stake, cages, or other options, the extended parts will crawl on the ground.

A chemical-free wooden stick with a bunch of rope would be enough. With its support, the extended portion will grow upward rather than sprawl on the ground and harm the fruit’s quality.

Step-7. Ascertain Pollination

At this stage, bees or other insects would have naturally pollinated if the plants were outdoor.

To conduct pollination indoors, you can tap the stem with your finger so the flower’s pollen would spread all around.

Otherwise, you can use the Q-tip method, a vibrating device that occurs pollination or just shaking and rubbing the stems to befall pollination.

Step-8. Restrain Pests and Prune the Tomato Plants

If you see any pest attack, you would need to immediately spray a chemical mixture or insecticides to protect the seeds or fruits.

There is no need to start pruning as long as they are not demotivating the growth.

But you will know by identifying yellowish marks on leaves and stem that the plant needs pruning. Instead of using any sharp metal, bend that portion to clear it away.

Extra Tips on Maintaining

We know how the additional hacks make things unexpectedly easier. Here we present a few tips that will help you maintain the growth effortlessly.

  1. Mixing earthworms, coir, eggshells naturally enrich the soil’s nutrition.
  2. If you don’t want pests in your grow room, you might want to choose a hydroponic system instead of soil mixtures.
  3. Plant 2 or 3 extra seeds, so if one goes misplaced or fails, the other would sprout.
  4. You will get a better result in tomato production with soil mixed with fertilizer. I always choose Jobe’s Spikes while growing tomatoes and never been disappointed.

What if I go on a Vacation in the middle of Their Growth?

You might eagerly be waiting to have a bite of fresh tomatoes and, at the same time, have an urgency to leave your plants all alone at home.

With modern science collaboration, you can travel for days while the automatic systems will take care of your plants.

Having a certain amount of water every day for moisture soil is genuinely essential for tomatoes. Therefore, you might set up an automatic watering system that will keep watering your plants even in your absence.

Besides, providing plenty of lights every day should not be considered while you are away. There are timer lights available in the market. You can control the schedule and duration of time with it.

The good thing is, other than vacations, you can generally use these items. It will go easier on your regular to-do list and will limit the chance of any risk.

How to Reserve the Tomatoes?

After taking up all the hassles to enjoy your own fresh tomato recipes, you must be thinking of a way to preserve it till the next flow.

So, let’s go and reserve all your hard work of two months so that you can enjoy it for the minimum to maximum possible time.

Short-term Preserving

To store the ripe tomatoes, avoid keeping it in the refrigerator in the first place.  Because the flavor and juice inside dry out, and ultimately the taste gets spoiled.

So, you can leave the tomatoes single-layered, slightly far from each other at room temperature.

In this way, you can go from a couple of days to a week. Ripen tomatoes will attract bugs, so don’t forget to take extra measures to protect the fruits from them.

Long-term Preserving

About preserving the tomatoes for a long time, collect the ones from your last session. It is best to pick while they have not ripened yet.

You can store them in zip-locker bags after removing the excess air inside so that the flavor would not get spoiled so fast.

You can plan to use them for a month in this way.

But for more, you might want to crush and turn the tomatoes in all of your favorite sauce recipes and enjoy them longer.

Frequently Asked Questions

Can tomatoes grow in 24 hours of light?

According to several research pieces, they keep growing as long as (24 hours) the light is available. A specific gene exists in wild tomatoes, which increases the yielding of nearly 20% more. If not possible, 16-18 hours for seedlings are still okay.

Can Cherry tomatoes be grown indoors?

Cherry tomatoes require massive sunlight to thrive. That is why it will grow fine indoors if sufficient artificial lighting sources are there to replace sunlight and make it thrive.

Is it possible to grow tomatoes indoors all year?

You can grow tomatoes indoors all year, no matter if the season is for tomatoes or not. As long as there are enough light sources and accurate temperatures, you are all good to go.

Can tomatoes recover from overwatering?

Ans. Luckily, tomatoes can recover from overwatering and it takes a minimum of one week to heal naturally.

What is better to grow tomato- container or ground?

There is no alternative to grow a plant under sunlight on a vast ground. As it will have more nutrition from the soil and enough light to grow. In contrast, the container will have limited soil and sunshine. Still, indoor growing in a container has its particular beauty as it helps in producing healthy tomatoes all year-round.

In Closing

Lastly, we have tried to cover everything you need to do or follow from the seeds to fruiting. Besides, we have shown you how to overcome some of the difficulties.

The success of getting the best result depends on your constant check and taking care of the plants.

But of course, this is the least activity you could do to enjoy those fresh red tomatoes at your dinner table while they are out of season.


Commercial tomatoes productions

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