Growing Tomatoes Indoors From Seed


Few foods taste better than homegrown tomatoes. Unfortunately, a lot of people think you can only grow your own tomatoes during the summer months outdoors. This is not true. You can grow tomatoes indoors, even in the dead of winter, if you follow a few guidelines that will keep your tomatoes strong and producing fruit.


Step 1

Moisten your seed potting soil so that when you take a handful and squeeze it, only a drop or two of moisture comes out.

Step 2

Poke a drainage hole with a pencil in each styrofoam cup you plan to use. Fill each cup with the moist potting soil.

Step 3

Plant your tomato seeds 1/4 inch deep, with four to six seeds per cup. Gently cover the seeds with soil. Label the different varieties you are planting by marking each cup.

Step 4

Place the cups in a warm location with temperatures ranging from 75 to 80 degrees F. Tomato seeds germinate best at temperatures around 80 degrees F. Keep the soil damp, not soggy.

Step 5

As soon as your tomato seeds have sprouted, place them 4 to 6 inches under high-pressure sodium fluorescent lights for 18 to 24 hours per day.

Step 6

Transplant your tomato seedlings into 6-inch containers when they are 1 1/2 to 3 inches tall. Fertilize them with a 50-percent diluted liquid fertilizer formulated for tomatoes or vegetables.

Step 7

Place the 6-inch pots with your seedlings under fluorescent lights for 18 to 24 hours a day with temperatures between 70 to 75 degrees F.

Step 8

When your tomato plants have grow to 12 inches, transplant them into larger containers.

Fruit Production

Step 1

Feed your tomato plants a mixture of 10-52-70 formulated food if the plants have not produced blossoms after 60 to 75 days. Feed them half the recommended strength every time you water your plants for two weeks. This will encourage your tomato plants to begin forming blossoms.

Step 2

Gently shake your tomato plants when they are flowering, holding the main stem, to help pollinate the flowers. Do this every few days when flowers are open.

Step 3

Fertilize your tomato plants throughout fruit production with a 16-16-16 formula, according to instruction on the package.

Things You'll Need

  • Tomato seeds
  • Standard potting soil or a seed-starter potting soil
  • Styrofoam cups
  • 6-inch pots
  • Fluorescent lights
  • 1- to 5-gallon containers
  • All-purpose vegetable fertilizer
  • 10-52-70 fertilizer


  • Jason's Indoor Guide to Organic and Hydroponic Gardening: How to Grow Tomatoes Indoors

Who Can Help

  • Harvest Wizard: Crack Resistant Tomato Varieties
Keywords: indoor tomato growing, tomatoes all year, growing tomatoes inside

About this Author

At home in rural California, Kate Carpenter has been writing articles and web content for several well known marketeers since 2007. With a Bachelor of Fine Arts degree from the University of Kansas and A Master of Education equivalent from the University of Northern Colorado, Carpenter brings a wealth of diverse experience to her writing.