Beginner Tips for Growing Tomatoes Indoors Year Round

Tomatoes do well when grown outdoors in warm climates and it only takes three to five months to mature into fruit-producing plants. Rather than waiting for a full year until when summer arrives to plant tomatoes, you can simply use some part of your indoor space to do all-season tomato gardening.

Tomatoes can be grown indoors as long as you have ideal conditions that support the healthy growth of a plant. The indoor gardening area is supposed to have enough natural or artificial light, free air circulation, and access to adequate water.

Choosing the right tomato variety will also determine the success of your indoor gardening.

Growing tomatoes indoors

Can you Grow Tomatoes Indoors?

Naturally, tomatoes do well during summer when the weather conditions are warm and sunny. They need at least six hours of direct sunlight. However, you can still enjoy your fresh and natural indoor homegrown tomatoes throughout any season in the right indoor conditions.

Here’s what’s needed

Sunlight or artificial lights

To maximize the production of tomatoes, it is important to expose the plant to sunlight or artificial lights. Tomato plant requires at least six to eight hours of sunlight per day. Therefore, when planting them indoors, you have to select an area that is near a big window or has transparent glass roofing.

If your indoor gardening area doesn’t have enough natural light, you have to consider the installation of artificial lights. Light is very important to any plant as it is necessary in the process of photosynthesis.

Tomatoes may become leggy and weak when they are planted in an area with poor light. They will be struggling to stretch toward the source of light.

Warmth and humidity

Temperature is an important factor to consider when intending to grow tomatoes indoors. Tomato plant does well in warm areas. Therefore, the room temperature has to range between 70 and 80 Fahrenheit. Humidity is easily controlled in an indoor area.

Watering or irrigation

Tomato plant requires adequate water throughout all stages up to maturity. However, the soil or the planting mixture is not supposed to be too wet or soggy. It is supposed to have a good drainage. Adequate and consistent soil moisture helps to prevent the tomato fruits from cracking or splitting and some diseases like blossom end rot.

Free air circulation

Tomatoes planted indoors are more susceptible to fungal infections as compared to their counterparts that are grown outdoors.  To avoid such infections, you have to ensure the area has free air circulation. A humidifier or running a small fun can help to circulate air in your indoor garden.


For first and healthy growth, tomatoes require fertilizers. When practicing indoor gardening you may consider the use of organic fertilizers to produce natural tomato fruits. Tomato plants are heavy feeders, therefore you may use an organic slow-release fertilizer. Nitrates are important, especially during the flowering stage.

Care and maintenance

Tomato plant requires routine care and maintenance that include: pruning the small branches that are growing on the main stem, rotating the plant to ensure all the sides receive sunlight, checking the dryness of the soil or the planting mix, and inspecting for pests and diseases.

Pruning is only recommended on the tall and vining tomato varieties. However, you are not supposed to prune the micro dwarf tomato varieties. Pruning can be done using your fingernails or punning shears.


Naturally, bees and birds help in pollinating your plants when they are grown outdoors. However, when you plant your tomatoes indoors, you have to find a means of helping with pollination.

Although tomatoes are self-pollinating, you can aid the process by gently shaking the stem of the plant during the flowing stage. Alternatively, you can use a cotton ball to dab on the blossom and move from one bloom to the other.

Tips for growing tomatoes indoors

Growing tomatoes indoors can be as easy as outdoor gardening. Here are important tips to follow:

1. Preparing the seedling

Fill the starting trays with a layer of soilless planting mix and dampen it. Avoid using topsoil and it may harbor pests and diseases. Plant two or three seeds in a hole ¼ inch deep in the planting mix. Transfer the trays to a warm area. Alternatively, you can place them on a heat mat.

2. Allow the seeds to germinate

The germination process can take 5 to 10 days for the seeds to sprout. However, you must ensure they are in an area that is warm, moist, and aerated. Don’t worry about the light during the germination process. Transfer them to an area that has light after germination.

3. After 4 weeks, transplant the seedlings into large pots

Separate the seedlings from the starting tray and transplant them into large pots containing a planting mix. Avoid any damage to the roots during the process of transplanting. Place the transplanted plants in an area that is warm and lit.

4. Water the tomato plants regularly

After transplanting your seedlings, ensure that they get enough water. You can use your finger to find out if the planting mix is dry before watering. Too little or excessive watering can cause plants to wilt, and have stunted growth, poor root development, low yields, and even diseases.

5. Apply fertilizer

After transplanting, wait for two weeks before applying any fertilizer. It is recommended to use organic fertilizers if you want natural tomato fruits. Tomato plants are heavy feeders, therefore fertilizer application should be redone every two weeks.

6. Watch for pests and diseases

Tomatoes are prone to different types of pests and diseases. Checking your plants regularly and taking the necessary measures helps to keep them in control.

7. Use stakes to support your tomato plants

When your tomato plants have outgrown the pots, it is high time to support them using stakes. Drive a stake into the planting mix next to the plant and use twine to tie it. This helps the plant to grow in an upward posture.

8. Prune the tomato plants

Some tomato varieties require punning while others are not. Pruning helps to ensure there are no excessive branches on the main stem. It also allows the plant to get light in all areas.

9. Harvesting the tomatoes

Harvest your tomatoes before ripening fully. Allowing them to ripe fully before harvesting can cause a crack that may attract insects. To harvest your tomatoes, you simply hold the tomato at the stem and twist it. Place the harvested tomatoes in a cabinet and allow them to ripen fully before use.

Which tomatoes grow best indoors?

There are different varieties of tomatoes. Some like Cherokee purple tomatoes can grow upward to over 10 feet tall. Therefore when having a limited indoor space, you can go for the dwarf varieties that grow between six inches to one foot tall.  The common varieties for indoor gardening include:

  • Red Robin
  • Florida petite
  • Tiny Tim
  • Toy boy
  • Sun Gold
  • Jelly Bean
  • Juliet
  • Pear

The dwarf tomatoes are ideal for indoor gardening. You can purchase the seeds online or near an agro vet shop near your locality. The micro dwarf tomatoes can vary in color from red to orange, or purple to green.

Final Thought

Successful indoor gardening for tomatoes requires some specific conditions. The gardening area needs to have sufficient light, warmth, and free air circulation. For the tomatoes to thrive, you’ll need to provide good care including watering, fertilizing, and pruning as needed.


Growing Tomatoes – The University of Arizona Cooperative Extension

Tomatoes Growing Guide – Cornell University

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *