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How to Start an Indoor Tomato Garden: 2 Easy Methods for Growing Tomatoes Inside

Tomato gardens are fun to plant, a joy to care for, and one of the most satisfying experiences to eat from! You get to literally eat the fruits of your labors. What could be better? Not everyone, however, has the privilege of having a huge backyard to plant rows and rows of tomato plants—but the good news is that you can start your very own indoor tomato garden!

Indoor tomato garden

If you’ve ever wondered how to start an indoor tomato garden, keep reading for my detailed guide!

Why Start an Indoor Tomato Garden

Indoor tomato garden

There are many wonderful reasons to start indoor tomato gardens, so let me just list a few:

  • If you don’t have a lot of space outside, indoor tomato gardens are perfect for those sunny spots in your kitchen, or any other warm space indoors. Indoor tomato gardens make gardening more accessible for those of us who don’t have a giant backyard.
  • You have control over the climate and weather indoors, which makes caring for your tomatoes a little easier. Whether your indoor tomato garden is in a greenhouse, or actually under your roof, you don’t have to pay as much attention to bothersome weather, extreme temperatures, and more. That means that you don’t have to keep track of rainfall to make sure you’re not overwatering your plants, because you know that the only water they’re getting is the one you’re giving them!
  • Indoor tomato gardens are more protected from pests, diseases (only if you buy certified disease-free transplants), and wildlife (unless you have unruly cats!). Just make sure to keep the windows closed, or use screens!
  • You yourself will probably be more comfortable while gardening, because you will also be under the shelter of a rooftop. Hopefully that means fewer sunburns and a more flexible gardening schedule!
  • You won’t have to winterize your tomato plants when the fall season ends, because hopefully your indoor space doesn’t get all that cold!

Types of Tomatoes for Indoor Tomato Gardens

Indoor tomato gardens

Now that I’ve hopefully given you one too many reasons to start an indoor tomato garden, the next step is determining what tomato varieties to choose.

The biggest differentiating factor in this decision regarding indoor tomato gardens is whether you’ll be growing determinate or indeterminate tomato plants. If you don’t know the difference between the two, it’s an important concept to understand, so keep reading. If you’re already all set on the determinate and indeterminate tomato situation, feel free to skip to the next section!

Determinate tomatoes differ from indeterminate tomatoes in several characteristics that I think make them better suited for indoor gardens. To begin with, determinate tomatoes have a self-pruning gene that makes them only grow a determinate amount (hence their name). They grow bushy, don’t always need support systems (unless their fruit gets very heavy), and grow all of their tomatoes all at once.

Indeterminate tomatoes, on the other hand, grow indeterminately until it gets cold enough that the plant understands to stop growing its fines. They don’t have the determinate tomato plant’s self-pruning gene, and put out fewer tomatoes, though they do so continuously throughout the entire growing season. Indeterminate plants require heavy-duty support to keep their vines and tomatoes off the ground, and dry.

So why do I think determinate tomatoes are the better choice for indoor tomato gardens? It comes down to the kind of space you’re dealing with. Chances are that your indoor space isn’t big enough to house the kind of trellises, cages, or other supports needed by indeterminate tomato plants. Determinate tomato plants, though, remain relatively small and bushy, so they all around require less maintenance. Plus, if you want to plant your tomato plants in containers, determinate tomatoes require smaller pots. Indeterminate tomatoes are trickier to plant in containers.

The good news is that determinate tomatoes are also the go-to choice for gardeners growing tomatoes for culinary reasons. Since determinate tomatoes put out all of their tomatoes at once, you can get straight to cooking, instead of having to store them and wait for the next harvest, as you would have to with indeterminate tomato plants. So it’s a win-win for you!

So when you buy either tomato seeds or a young tomato transplant, make sure to read the guideline to see whether you are acquiring a determinate or indeterminate tomato plant. Sometimes, the former is called “bush tomato,” and the latter is called “vining tomato.”

How to Start an Indoor Tomato Garden

Indoor tomato garden

Now that you’ve chosen either a determinate or indeterminate tomato, let’s get started with growing an indoor tomato garden!

The first step is to determine a location. For those of you who don’t have greenhouses, find a location within your home that receives at least between eight to 10 hours of sun each day, and whose temperature fluctuates between 50 and 90 degrees. Tomatoes are warmth-loving plants! It might also be worth finding more than one such spot in your house, in case the light changes so dramatically each season that the original spot you chose isn’t appropriate throughout the entire year.

Next, you can choose to start your indoor tomato garden either from seed or with a transplant. That means either germinating seed or buying a small plant. The latter option clearly accelerates the whole timeline, but both methods work well and it’s just a matter of personal preference!

From Seed

If you’ve decided to grow your tomato plant from seed, the process starts a little earlier. You’ll want to plant them in either seed trays or other small containers (egg cartons are a great option!) about six to eight weeks before the last winter frost (even though frost impacts indoor tomato gardens less).

Using potting soil for seed starting, plant the seeds one-fourth of an inch down, and consider using grow lights if you don’t have any particularly warm and sunny spots in your home.

You should start to see your seeds germinate between one to two weeks, and you can then transplant them into their next container when they are at least six inches tall by following the same guidelines as planting transplants below. Determinate tomatoes will need a container of at least five gallons, whereas indeterminate will need a much bigger one. Do some research specific to the tomato variety you have chosen.

From Transplant

If you decide to buy a tomato transplant, then you essentially skip the section above. After the last winter frost, go to your local nursery or online a buy a young tomato plant. Choose one that is healthy, strong-looking (not wilted or damaged), and free of creepy crawlies. Do some research into what container size works best for your tomato variety specifically.

At home, remove the leaves closest to the base of the plant, and plant two-thirds of the transplant into quality tomato potting soil within a container. Tomatoes are special plants—they can grow roots along any part of their stem, as long as it’s buried beneath the soil!

Caring for an Indoor Tomato Garden

Indoor tomato gardens

Now that you’ve kick-started your indoor tomato garden, it’s all about care and nurturing!

Watering

Whether starting from seed or using a transplant, the soil should always be moist but never soggy. Test the soil with your finger to determine dryness, and remember that potted plants dry up faster than plants planted in soil. Water the plant at its base, as opposed to splashing it over the leaves.

Though it’s less important for indoor plants, a rule of thumb for watering is to water early in the morning to allow the plant as much time as possible to dry off any excess water on its foliage before nightfall. Overnight wetness could cause rot or the spread of disease on plants!

Fertilizing

Tomatoes are hungry plants, so fertilizing is an important part of caring for your indoor tomato garden. Choose a quality slow-release fertilizer that isn’t too heavy in nitrogen, which tends to encourage foliage growth as opposed to fruit production. Feed throughout the growing season.

Pruning

As mentioned earlier, determinate tomato plants have a self-pruning gene that pretty much takes care of their pruning needs. So if you’ve chosen a determinate variety, you don’t need to worry about pruning your indoor tomato garden. Just keep the pot clean by removing dead foliage.

If you’ve chosen an indeterminate variety, however, I advise that you remove suckers to train the plant’s growth and encourage thriving fruit production. For a more detailed guide to pruning your indoor tomato garden, read our tomato pruning guide.

Pests and Diseases

As mentioned earlier, one of the advantages of growing an indoor tomato garden is that plants are naturally protected from pests and diseases. Still, you should monitor them for signs of creepy crawlies or other afflictions, especially if you grow your indoor tomato garden close to other house plants. For specifics, read up on common tomato pests and tomato diseases.

Now You Know How to Start an Indoor Tomato Garden!

Congratulations! By following this guide, you have officially started your indoor tomato garden and can look forward to a plentiful and delicious harvest. Have you decided how to consume your tomatoes yet? The options are endless! Indoor tomato gardens are a great option for those without the luxury of a big backyard, but they are also convenient for any gardener who doesn’t want to have to fight with the outdoor environment all the time.

Looking for more growing guides? Check out our tomato section to learn more!