How to Grow Tomato Seedlings Indoors

There are numerous varieties of tomatoes. However, they can be classified into two basic categories: determinate (bush) and indeterminate (vine). Whether you are growing indeterminate tomatoes or determinate tomatoes, you can grow tomato seedlings indoors and then transplant them outdoors.

There are five stages of growing tomatoes.

  • Sowing seeds
  • Fertilizing seedlings
  • Transplanting seedlings
  • Taking care of tomato plants
  • Harvesting fruits

Generally speaking, tomatoes grow in the winter, however, the seedlings cannot tolerate harsh cold. Some varieties of tomatoes grow in the summer, however, the seedlings cannot endure too much heat. However, you grow seeds indoors throughout the year by creating a microclimate.

Sowing seeds

You can sow tomato seeds in a seedling tray or any kind of flat container. If you are using a seeding tray, fill it with potting mix and toss one seed on each hole.  If you are using a flat container, fill the container with potting soil and sprinkle tomato seeds thinly. You will have to avoid sowing the seeds densely; when you sow seeds densely due to lack of space between the seedlings, the seedlings will grow thin and are very weak. When you are not using a seeding tray and want to avoid sowing densely, you can add two spoon sand in own spoon of seeds mix well and sprinkle the seeds in the seedling bed or soil. After you sprinkle seeds on the soil, add a thin layer of potting soil and mulch. The water thoroughly. You can also add insecticides in the water to water your seeds. This will prevent ants and other insects from eating the sees. One of the major problems while growing tomato seeds is saving the seeds from ants and other insects. Therefore, you should take extra care while sowing tomato seeds. You can use disinfectant on the potting soil or spray disinfectant after sowing the seeds. You can also speed up the germination process by covering the soil with peat moss or plastic sheet. If you are using the plastic sheet, remove the sheet when you see the sprouts.


When the tomato seedlings become one inch, feed them. You can use compost, compost tea, or artificial fertilizer. Tomato seedlings need nitrogen, therefore, make sure your fertilizer contains a good level of nitrogen. You should also water your tomato seedlings regularly. However, do not make the soil soggy.


Tomatoes seedlings need repotting. Repotting is done in two stages.

Transfer the seedlings to another container when the seedling is two inches. Tomato seedlings become two inches tall in two weeks if you have given them good fertilizer and water.

Now, you can plant the repotted tomatoes in the soil or container of your choice. This is generally in two weeks after the first repotting.

You should give them fertilizer after the roots have settled which is generally in 4-5 days. Phosphorous in the soil aids the healthy growth of seedlings. Your seedlings need a lot of phosphorous to grow well. Thus, while preparing the potting soil, you need to add phosphorous to the soil if it does not have a healthy proportion of phosphorous. Wood ash contains phosphorous, you can add wood ash to the soil. Water the plants regularly. Your tomato seedlings should also get a good amount of light.

Taking care of tomato

Tomato is prone to mildew and other fungal diseases. Caterpillar also causes the risk to tomato plants. You should provide water and fertilizer to the tomato plants in the flowering and fruit-bearing stages.


The first harvest will be ready in 90-120 days of sowing the seeds.


Whether you are planting seedlings outdoor or growing plants indoors, you can start indoor seedlings. Indoor seeding is best for plants that need warmth during the growing season. Indoor seedling is also a better option for growing seeds if mildew is a problem in your area. If you are in a dry area and your plants need humidity, indoor seedling is a better option. One of the major benefits of growing seedlings indoors is you can save your plants from insects and extreme weather. In the controlled environment indoors, plants grow easily. You can even grow the plants indoors. It has been found that indoor plants produce a better harvest.

5 thoughts on “How to Grow Tomato Seedlings Indoors

  1. I have always wanted to grow vegetables indoor, however, I have never tried this myself. I might stat with tomatoes. Thanks for the tips

  2. I have tried growing tomatoes in my backyard . However, i have never tried growing seedlings indoors. Since tomatoes seeds have low germination it is very difficult to grow seeds.

  3. My dad is fond of farming and I’m surely doing to share this post with him. Excellent insight on dos and donts. Good read.

  4. I have always wanted to grow vegetables indoor, however, I have never tried this myself. I might stat with tomatoes. Thanks for the tips

  5. I always fail to manage outdoor tomatoes also indoors, the tree thrives but does not succeed in fruiting! I hope with the explanation of this article I have successfully planted and produced fruit. thank you

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