How to Grow Tomatoes Indoors, According to Expert Gardeners

Few things compare to the taste of a vine-ripened tomato. Sure, you can get one from your local farmer’s market or from a generous neighbor who likes to share their bounty. But if you lack the outdoor space and want to give tomato growing a try, you are in luck.

With a little preparation, it’s entirely possible to grow tomatoes indoors from seed. We spoke to two gardening experts who provided some tips to make the process easier. Follow along with this step-by-step guide.

Why Grow Tomatoes Indoors?

Outdoor space isn’t the only reason why some people can’t grow tomatoes outside. “In Britain, many people choose to grow their tomatoes in greenhouses, polytunnels, or inside the house because it’s warmer and protects the plants from getting blight, a fungal disease,” explains gardener Tanya Anderson. This is also true for many people who live in colder climates with short summers.

Depending on the variety, tomatoes can take anywhere from 50 to 80 days from seed to harvest. “Growing a pot or two of cherry tomatoes in the conservatory or enclosed porch is practically a tradition, but they do well placed next to a sunny window, too,” says Anderson.

However, do not expect a big harvest. “I would consider it just for fun, not for any substantial amount of food,” says garden writer Melissa Will. Nonetheless, Will says growing tomatoes indoors is fun. Plus, these tomato plants have the potential to bear fruit throughout the year since there is no outdoor risk of freezing.

Considerations Before You Get Started

Tomatoes are warm-season plants. Thankfully, most homes have temperatures that range from 65 to 80 degrees Fahrenheit. The plants do well in average humidity, too. As long as your potted tomatoes are getting the right amount of light and water, the temperature and humidity in your home should not be an issue. However, keep the plants away from air vents so it is not exposed to hot or cold drafts.

Light Requirements

Tomatoes need a minimum of six hours of light per day to produce fruit, but eight or more hours of light will have the best results. Unfortunately, the quantity and quality of light are the biggest hurdles in growing tomatoes or any sun-loving plant indoors. For best results, place the potted tomatoes next to a large south-facing window. Rotate the pots often so that the plants grow evenly and do not lean toward the light.