How To Grow Tomatoes Indoors and Succeed Anytime

Who doesn’t love tomatoes?

Did you know that In 2019 the United States was ranked number 1 in the Import of Fresh or Chilled Tomatoes

US tomatoes consumption

US tomatoes consumption from 1991-2019

The only problem with that statistic is that if you live in the US, you are most likely eating an imported tomato that took a while until it got to your plate. The thing is, you can grow tomatoes indoors, and it is not that hard.

But there is a catch…! 

Tomatoes belong to the family of crops that grow in warm seasons. The crop tends to die when cold weather arrives. Therefore, you cannot enjoy freshly homegrown tomatoes in the winter. 

The produce will be very small and much less prolific than summer tomatoes. 

Therefore, you must plan your indoor winter tomato cultivation to ensure season-long results. Some tomatoes are better for home growing, and you need to go with them during winter cultivation. 

Tomato plants are extremely sensitive to cold temperatures. So, it would be best if you handled them with great caution to keep them alive throughout the year. In this guide, we will discuss various aspects associated with homegrown tomatoes in winter. 

Can You Grow Tomatoes Indoors?

tomato plant

When winters arrive, the growing season for tomatoes might be over, but this shouldn’t stop you from keeping the fresh produce coming to your plate. With central air conditioning systems, the temperatures inside our homes are pretty much warm. This warm air circulation serves to be the perfect condition for growing indoor tomatoes.

You need suitable varieties of supplies and light conditions to confirm those plants can produce juicy fresh tomatoes. So, yes, you can grow tomatoes indoors even when it’s cold outside. 

You can either find a perfect spot inside your home that is exposed to plenty of sunlight throughout the day. Or you can use a grow tent kit, a grow cabinet, or a box to create proper light using artificial grow lights. Both techniques can produce beautiful results.

In the case of hydroponics, you can either go for a soil-based growing medium or a soilless growing medium, such as water. Hydroponics uses a water-based solvent of minerals and nutrients to feed plants and help them grow. 

Instead of soil, water serves as a medium here, making the entire indoor growing process much easier. It is a much more favorable option to consider because tomatoes require rich soil that needs to be very high in quality.

Another advantage of hydroponic technology over soil-based growing is that you don’t have to deal with any pests or bacteria that thrive in the soil. Therefore, you won’t have to use any pesticides or chemical-based fertilizers. So, hydroponic technology can grow more organic and healthier food. 

Best Tomatoes to Grow Indoors

type of tomato

You must remember that not all vegetables grow very well in indoor gardens. Therefore, you need to be careful when buying your seeds. For the best results, you have to go for smaller varieties of tomato plants. 

Several varieties of tomato seeds can be grown indoors, including:

Cherry Tomatoes:

These are small, sweet, and very easy to grow indoors. They can be grown in pots or hanging baskets and don’t take up much space.

Some popular cherry tomato varieties include Sungold, Sweet 100, and Yellow Pear.

Dwarf Tomatoes:

These are compact plants that are perfect for growing indoors. They stay small and are ideal for small spaces.

Some popular dwarf tomato varieties include Dwarf Cherry, Tiny Tim, and Pixie.

Patio Tomatoes:

These are slightly larger than cherry tomatoes and are perfect for growing on a windowsill or patio. They are also ideal for growing in pots or hanging baskets.

Some popular patio tomato varieties include Patio, Patio Choice, and Patio Princess.

Bush Tomatoes:

These are also known as determinate tomatoes, which are known for producing a concentrated set of fruit that ripens all at once. Some popular bush tomato varieties include ‘Bush Beefsteak, Bush Early Girl, and Bush Goliath.

No matter which type of tomatoes you go for, you have to be sure that the temperature, moisture, and light conditions are perfect, or you won’t be able to get anything substantial during the harvest. 

Can You Grow Tomatoes From Store-Bought Tomatoes?

tomato seeds

Saving your tomato seeds from the pulp and using them for growing a new batch of tomato plants indoors isn’t that big of a deal. But you need to be careful to start with suitable varieties of tomatoes. Therefore, you can’t just grow tomatoes from store-bought tomatoes. 

These ordinary store-bought tomatoes are not the best for seed saving. These tomatoes are F1 hybrids. F1 Hybrids are the 1st filial offspring generation of parental plants of distinctly different types. If you grow from these tomatoes, your batch will differ from the original plant. 

Instead of these F1 hybrids, you need to look for open-pollinated or heirloom seed varieties, which you can find at different nurseries and gardening shops either online or in-store. This variety of seeds will produce a batch close to the original plant. 

Of course, if you are growing for the first time, you will need to buy these seeds from a shop. Seed companies that specifically produce these varieties of seeds should be your highest priority. Therefore, always check the packing or the website for such seeds, or you will ruin the produce. Later on, you can use the seeds from your grown tomato by following the steps listed below.

You can also use an indoor growing system that can make growing tomatoes a really easy task. Some of those smart gardens already come with tomato plant pods.

How To Save Tomato Seeds?

  1. Scoop out the seeds from the tomato and spread them on paper to dry. Fermenting these seeds would be easy, and you can end up with a cleaner group of seeds. It makes the storage and trade of these seeds a lot easier. But make sure to only use fully ripened tomatoes for seed scooping. 
  2. You must place your tomato upright and slice it horizontally in half right through the middle.
  3. After that, scoop the seeds out in a ceramic container. It will keep the seeds wet and covered.
  4. Add a couple of tablespoons of water to it. Cover the container with plastic wrap and poke holes using a fork. 
  5. Let the seeds be in a warm place for five days but not in direct sunlight.
  6. After 5 days, you will see that it has developed a mold layer. The layer of mold can either be thick or thin and have a terrible smell, but you don’t need to worry about it. Just remove the wrap and get rid of the mold using a spoon.
  7. Now, place the container under a gentle stream of water. You will notice the seeds will sink at the bottom. 
  8. Clear the water from the top by pouring it off gently. Make sure the seeds are thoroughly rinsed. You can also use your fingers to eliminate any stuck pieces or pulp. Use as much water as possible to get them clean.
  9. Place these seeds on a coffee filter to dry out any remaining water. You shouldn’t use your kitchen roll for this purpose, or your seeds will get stuck.
  10. When the seeds are completely dry, rub them on the coffee filter and store them in a plastic envelope. Keep them away from sunlight.

Steps for Growing Tomatoes Indoors

There are various steps involved in the process of growing tomatoes indoors. You have to be extremely cautious if you want your plants to achieve full yield. 

Step 1: Find the Perfect Spot 

grow tomatoes indoor by the window

Before gardening, you will have to find the perfect spot (usually a sunny window) in your home where plenty of sunlight is available throughout the daytime. Your tomatoes will not grow at all if you don’t serve them in the right conditions. So, a sunny window is key here, and make sure to place it in a south-facing window. 

Even if you want to grow hydroponic tomatoes, you will have to provide them with proper light, moisture, and temperature. Your plants need at least 8 hours of sunlight or 16 to 18 hours of artificial light to grow properly. They need their surrounding temperature to be around 70F. You can either go for sunlight or grow lights for this purpose.

Step 2: Pick the Right Seeds

Again, before gardening, pick the right kind to grow tomatoes indoors. Make sure you get the most out of your harvest.

Step 3: Begin with Germination

The next step in the gardening process to grow tomatoes indoors is to plant your seeds for germination to ensure they enter into their full growth mode.

Tomato seeds need three conditions to germinate. Those are warmth, water, and oxygen. 

They do best when they are planted in warm soil that is lightly moistened. The soil temperature should be a minimum of 75 degrees Fahrenheit for most plant species to sprout well.

Tomato seeds do not need light exposure to sprout and do better in moist soil than in dry, cracked earth. It’s essential to water your tomato seeds often, so the soil doesn’t dry out. If your tomato seeds are not germinating, that’s probably because it lacks sufficient water or warmth.

 This process is not needed in hydroponic techniques. 

Step 4: Make Some Room for Them to Grow

With the traditional soil-based methods, you will have to move the tomato seedlings into pots to ensure plenty of room for them to grow. You need to move these pots to the sunny spot you chose for your plants to grow. 

You can give them additional nutrients with the help of fertilizers after every 5 weeks. In the case of hydroponic tomato plants, you only have to set the temperature, light, and moisture conditions at the beginning and change them as your plants grow. 

Step 5: Make the Conditions Right

In case of growing under sunlight, you will have to change the sides of the plants exposed to sunlight each day, so each side grows normally. Just water them when you see the soil is dry. 

Step 6: Pollination

Outside in the natural environment, birds and bees help pollinate tomato plants but indoors, that is impossible. You will have to help spread the pollen with a soft brush or cotton swab, which is key to growing tomatoes indoors.

Step 7: Picking up

For the best flavor, leave the fruits on the plants for as long as possible, which means when they turn to the correct color, bright red, orange, or green. If some green falls off, they will eventually ripen while stored in a warm place outside direct sunlight. You need to grab a tomato from near its stem and twist it. The tomato will snap off!

Step 8: Keep the Cycle Going

When you grow tomatoes indoors, they continue to produce fruit for an extended period. So, you don’t end your experiment right after your first harvest. If you take proper care of your plants, they will continue to provide you with season-long, fresh, and juicy fruit.

How Many Tomatoes Will One Tomato Plant Produce?

The average yield per square inch for hydroponic tomatoes is around 40 pounds annually. Under optimum conditions, you can also go for a yield ranging between 46 pounds to 50 pounds per 1.4 sq. ft. Read more on how many plants per person you should grow for a year’s worth of harvest.

Tomato plants are very fragile and vulnerable, and you must take great care if they are in natural soil-based conditions. The yield will depend on whether you provide enough nutrients and light. 

Tomato plants under hydroponic conditions will perform best with up to 16 to 18 hours of light daily. They must also be watered via a drip irrigation mechanism or flood & drain system. The pH range for these plants under this technique ranges from 5.8 to 6.3. You can increase the pH level by using potassium hydroxide and reduce it by using phosphoric acid. Soil pH level is crucial as it influences different factors associated with the soil in plant growth. These factors include the likes of soil bacteria, soil structure, toxic elements, and availability of nutrients. 

Nutrients are most available in the range of 5.5 to 6.5. With growing numbers of bacteria and toxic elements, your plant cannot grow and will eventually die. Therefore you will have to maintain the pH levels in the soil. 

The daylight temperatures need to range between 65F to 75F, while the nighttime temperature should range from 55F to 65F. 

Also, make sure to change the nutrient solution weekly (or every two weeks), and for maximum yield, you can pollinate your hydroponic tomato plants using a soft brush for even better yield. 

How Long Does It Take to Grow Tomatoes?

A tomato plant grows best when the soil temperature is around 55F while the air temperature is around 65F to 90F. You can grow tomatoes from seedlings in these temperatures.

An indoor tomato plant can produce fruit for around 60 to 80 days. And you have to be precise in providing the plant with conditions that are close to what it naturally requires in the outdoor environment. 

Even a slight change in the temperature or light setting can alter the results significantly. There is not much difference in the time a plant takes to produce fruit in the outdoor or indoor environment. But if you want to enjoy a delicious-tasting fruit, you must provide the plant with the right conditions and pick the fruit at the right time.

What Kind of Light Do I Need to Grow Tomatoes Indoors?

tomato grow light

You might have noticed that we have emphasized that the surrounding conditions to grow tomatoes indoors need to be optimal for the best results. And as they are warm-weather plants, it heavily relies on sunlight. 

So, light is going to be crucial to grow tomatoes indoors. Therefore, when growing indoors, you must provide them with the best light conditions. Artificial light or grow light can be pretty handy in this regard.

If your plants don’t get enough light in the day, they will die. The optimal light in terms of lumens ranges between 7000 lumens to 7500 lumens per sq. ft. You need to give it at least 2000 lumens per sq. ft for a minimal amount of light. 

If you are using LED lights or fluorescent lights, they need to come with a broad spectrum of colors to support the plants at different stages of life. In the case of other lights, you must provide your tomato plant with plenty of light to produce as much fruit as possible. 

But this is mandatory during the growing stage only. And at the ripening stage, the plant needs sunlight. So, you must provide the plant with ample light during the growth stage.

Can You Keep A Tomato Plant Alive All Year?

When growing outdoors, you will have to rip them out at the end of the season because they can’t grow in cold weather. Growing them indoors allows you to keep them alive throughout the year. 

However, it would be best if you remembered that indoor tomatoes are significantly smaller than their outdoor counterparts that grow in summer (summer tomatoes). If you can move a tomato plant from outside to inside, you can also extend its harvest period and overall life. 

With the help of the succession planting method, you can keep indoor tomatoes going throughout the year and extend the harvest. But of course, for the best results, you must provide indoor tomatoes with the best light and weather conditions, just like their natural environment. 

With enough light, tomato plants can generate enough energy to produce as many fruits as possible. And if the light is not right, it won’t be able to produce much energy because the light is not enough. 


Growing indoor tomatoes is a pretty fun job because these are plants that don’t last an entire year. But with indoor growing, you can keep them growing the entire year. 

Indoor tomatoes need proper conditions close to their natural habitat, allowing them to grow in plenty of light and warmer temperatures. Also, keep in mind to use the best kind of tomatoes suitable for indoor growing. 

Usually, plum tomato plants, cherry tomatoes (including Tiny Tim and Red Robin), and vining tomatoes are the top choices for indoor growing. So, use the seeds of these tomato varieties for the best results. Furthermore, don’t get to harvest them when they’re green, and don’t wait for them to turn red because they can also ripen after the harvest. 

You can continue cultivating more seeds right after the first harvest to keep the cycle going throughout the year. For the best results, don’t forget to use the right kind of seeds and provide them with the best possible conditions closest to their natural environment. You will see juicy tomatoes growing even in winter.

Photo of author
Daniel Buckner is an indoor gardening enthusiast and hydroponic expert with years of experience cultivating a variety of plants. Passionate about sustainable living and urban gardening, Daniel shares his knowledge through engaging content to inspire and educate fellow gardeners. Discover the joys of indoor gardening with Daniel's practical tips and valuable insights.

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