How to Grow Tomatoes Indoors for Vine-Ripened Fruit Year-Round

·3 min read
tomatoes growing indoors
tomatoes growing indoors

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Do you love to grow tomatoes? You're not alone: Tomatoes are mainstays in many gardeners' plots—including Martha's. According to Martha, this bold, red fruit (yes, fruit!) delivers the taste of summer with every bite. "And, they're filled with excellent antioxidants and vitamins," she says. Since tomatoes—officially known as Lycopersicon esculentum—have a reputation for growing best during warmer seasons, you might be wondering if you can also grow tomatoes indoors.

Related: How to Plant Tomatoes at Home

Growing Tomatoes Indoors

If you love this delicious fruit and want to produce your own—no matter the time of year—you'll be happy to learn that you can grow tomatoes indoors. "However, you will need to mimic the ideal outdoor conditions for the tomato to grow tomatoes successfully and produce fruit," says Rebecca Sears, the chief gardening guru for Ferry-Morse. "That includes ample space for the root ball to grow, staking to keep the plant upright, good air flow and pruning, regular watering and feeding, and full sun."

Planting

Sears says that the tomato seed variety you plant will make a big difference in how it will thrive in your home. She suggests a natural, disease-resistant variety, like Better Boy Hybrid ($2.79, ferrymorse.com) and Big Boy Hybrid ($2.79, ferrymorse.com), as they reap deep red tomatoes from seed.

Here are some tips for successful indoor planting:

  1. Plant the natural, disease-resistant seeds in soil that provides adequate drainage. If you are short on space or large containers, Sears says to choose a determinate or a patio variety.

  2. Water the plant regularly (as much as needed to keep the soil moist).

  3. "Prune any side shoots between the main stem and side stems to redirect the energy to tomato production and to keep the plant from overgrowing your space," says Sears. Pruning will also help lead to bigger fruit, as new shoots can produce flowers instead (this causes stems to grow without tomatoes), says Levi Gardner, a professor of environmental studies at Grand Valley State University and co-executive director of Urban Roots, a non-profit community farm and education center in Grand Rapids, Mich.

Related: Five Mistakes You're Making with Your Tomato Plants

Lighting

"Tomato plants require full sun to grow properly and should be maintained at a temperature around 70 to 75 degrees," says Sears. If your home doesn't get the best direct sunlight, you will need to shine a grow light on the tomato plants for 16 to 18 hours a day to ensure they receive enough "sun" indoors. Otherwise, tomatoes will need eight to 10 hours of direct natural sunlight each day from inside the home.

Pollination

In order for the plants to grow fruit, they will also need pollination. "Without bees and wind to do the job, you'll need to help the process along by either using a small paintbrush to transfer pollen from flower to flower or using an oscillating fan to encourage the pollen to travel," Sears says. With all of these steps in mind, Sears notes that a tomato plant can live for nearly a year, however, expect the tomato production to slow down naturally over time.

Harvesting Tomatoes Indoors

Sears says that the color of the tomato itself will help you decide when it's time to harvest. And similar to tomatoes grown outdoors, tomatoes grown indoors should be harvested when they are completely ripe—this will result in the best flavor.

When most tomato varieties turn from green to red and start to soften slightly to the touch, they are ready to harvest. You can check the ripeness of the tomatoes further by giving them a light squeeze to test their firmness (the firmer the better). Once the tomato's ripeness is to your liking, Sears says to hold the stem of the plant with one hand and pull the tomato off with the other.