Indoor Gardening / Planting Guides

11 Top Tips on How To Grow Tomatoes Indoors With Lights

Learning how to grow tomatoes indoors with lights is an excellent idea if you want to enjoy fresh, juicy tomatoes during the winter. The best thing about this project is how easy it is; anyone can do it! These eleven tips will help you grow your own delicious, homegrown tomato plants indoors all year long.

Learning to grow vegetables indoors for beginners and learning to garden in an apartment are trends that have taken off over the past few years! Learning how to grow tomatoes indoors successfully is one of the most popular questions I am asked, and so it’s my focus in today’s article.

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1. Picking the Right Tomato Seeds

Choosing the best tomato seeds is one of the most important parts of learning how to grow tomatoes indoors with lights. There are a lot of different options out there, so it may be difficult to choose which ones will work best for your specific setup. As the first step, some good things to look at include:

Pick a Variety Resistant to Disease:

As you’ll be growing tomatoes indoors for an extended period of time, it’s important to choose a variety that is resistant to common diseases.

Determinate (Bush) Tomato Plant vs Indeterminate (Vining) Tomato Plants:

Determinate tomato plants grow to a certain height and then stop, while indeterminate plants keep growing. For growing tomatoes indoors, it’s best to pick determinate varieties as they are easier to maintain under the light of your indoor lamps. A couple of varieties I recommend are:

Pick Tomato Varieties that Work Well in Containers:

Tomatoes have deep root systems, so it’s best to choose varieties that work well in containers. That way, you can easily move them around as needed if they start to grow too large for their current pots under the lights.

tomato plant seedlings with the best soil for indoor tomatoes
The best soil for indoor tomatoes contains perlite for drainage

2. Pick the Right Soil

The best compost for indoor tomatoes is that which is not too compact, drains well and also provides essential nutrients. If you can, use a potting mix with some perlite in it to ensure good drainage. You can buy these types of soil mixes on Amazon, garden centers or big-box retailers. Search for a potting mix suitable for indoor growing. 

The best way to grow tomatoes indoors with lights is by making sure the soil stays moist but not wet, which can cause root rot.

3. Provide Proper Watering

Water plants thoroughly when you first plant them, then water again only if the soil feels dry an inch below the surface.

Another way to retain moisture is to use a soil and coir mixture. Coconut coir mixed through the soil doesn’t compact as much as traditional soil and also retains moisture ideal for tomato growing indoors. Use a moisture meter to test your plants and water accordingly.

4. Mix in Slow-Release Fertilizer

Before planting, mix a slow-release fertilizer into the soil to provide your plants with nutrients as they grow. This way, you don’t have to worry about fertilizing every week, as the fertilizer will release slowly over a long period of time.

5. Hand Pollination

Outdoor tomato plants pollinate well by themselves, however, for indoor plants because there’s no wind or bees so you need to pollinate by hand. Pollination is essential for abundant fruit production.

This is a very easy, albeit gentle process. What you need to do is help pollinate each flower by taking a small paintbrush or cotton swab/bud. Gently brush the pollen from inside the flower onto the stigma. To avoid being too intrusive and disturbing the flower, just gently tap on the flower stem to release the pollen.

These Be the Bee Pollinators are another fantastic way to artificially pollinate. By gently touching it to the back of each flower; it imitates the vibration a bee causes and helps spread the pollen. A small fan nearby can also do the trick, creating an artificial gentle breeze around the plant to simulate the natural process.

A bee pollinating a tomato flower, knowing how to grow tomatoes indoors with lights includes hand pollination
Hand pollination with an electric toothbrush mimics the works of a bee

6. Make Sure Your Tomato Plants Get Enough Light

The most important part of how to grow tomatoes indoors with lights is to make sure your plants get enough light. For growing tomatoes indoors, full spectrum LED lights are best.

The term full spectrum refers to the illumination spectrum that the panel produces, which includes various temperatures and sorts of LED chips that your plant will utilize during different phases of development. This actually imitates natural light.

Cool coloured lights (6500k) encourage and stimulate the germination and leafing process when growing indoor tomatoes, while warm colours (2700k) help simulate the flowering and fruiting. Use a combination of warm and cool bulbs for optimum plant growth.

AeroGarden LED lights are full spectrum LED lights that create the perfect wavelengths for growing tomatoes indoors all year round, and produce the best light for tomato plants.

Garden Tower also offer a great 80 watt option that can be positioned vertically or horizontally.

High Pressure Sodium (HPS) lights are also good when considering how to grow tomatoes indoors with lights. However, they provide more heat than LED lamps, so an indoor tomato plant may dry out faster under their light.

Consider Purchasing an Indoor Garden

If you’re looking for an easy indoor garden solution then there are some great done-for-you solutions available.

click and grow smart garden review of the smart garden 25
Click and Grow Smart Gardens make growing food indoors easy!

Indoor Smart Gardens

AeroGarden and Click and Grow are top brands of innovative indoor smart gardens. They are soilless gardening systems that use hydroponic technology to grow herbs and vegetables indoors.

These indoor smart systems feed and grow plants using LED grow lights and automated watering tanks – They seriously take all of the hard work out of growing vegetables!

You can check out my Aerogarden vs Click and Grow review to see which one might suit you.

Tower Garden Vertical Gardening

The team at The Garden Tower Project invented this incredible vertical gardening system that enables anyone to grow their own vegetables, no matter where they live!

Before and after images of the garden tower 2 growing vegetables in an apartment

In just 4 square feet, you can grow up to 50 plants including tomatoes! At the core of this design is a worm farm. It recycles food scraps and sustainably fertilizes plants from the roots. Then all that needs to be done is a regular water.

The Garden Tower 2 can be grown both outside or inside with LED lights, making it the ultimate space saving garden solution.

7. Temperature and Placement

Tomatoes grow best in warmer climates, so try to maintain a temperature between 70 and 85 degrees. Keep your plants away from vents and cold windows.

Tomatoes are sun-loving plants so it’s ideal to place the plants in the brightest area of your home- a sunroom or a sunny south facing window for growing tomatoes indoors on a windowsill works best. If this is not possible, try to expose your plants to Grow LED lights for 16 hours per day.

Yes, this is more than natural light (recommended 8hrs per day) as artificial light isn’t equivalent to the natural stuff.

8. Provide Good Support to the Plant

Tomato plants need support as they grow, so it’s important to provide them with something sturdy like tomato stakes. A tomato cage also works well for this purpose. Just make sure the top of it is open so that light can reach all parts of your plant.

Vine varieties can be grown up a string or wire. Look for cherry tomatoes and plum tomato varieties for indoor gardening, as these are the most compact varieties.

fresh tomatoes ripening on the vine in how to grow tomatoes indoors with lights
Harvesting fresh tomatoes grown indoors is so rewarding!

9. Harvesting Your Tomato Crop

How long does it take to grow tomatoes?

Be patient when it comes to harvesting your tomato plants. It takes about 80-85 days for an indoor plant to mature before it can produce fruit, so be sure to pick them when they look ripe and feel soft.

You may need a knife to cut the stems of some varieties if you’re harvesting them from above. Just be sure not to damage any foliage as this can harm your plants’ ability to grow more tomatoes later on.

Will tomatoes ripen under grow lights?

Yes, much like growing tomatoes outside, tomatoes will ripen under grow lights.

10. Pinch Back New Growth

Once you’ve harvested your tomatoes (which should happen about 90 days after transplanting), pinch back new growth to encourage more fruit production. You can also treat them with a plant hormone called cytokinin at this point in order to promote further flowering and fruit production.

11. Storing Your Tomatoes for Later Use

Once you’ve harvested your vegetables, you can store them in your refrigerator for a couple of days or pickle and can them.

To store tomatoes, remove any that have gone bad and place the good ones in a single layer on paper towels inside an airtight container. Make sure there is some space between each tomato so they don’t ferment or rot as you stack them.

tomato plants growing in an apartment window. how to grow tomatoes indoors with lights

Frequently Asked Questions

What are the best conditions for growing tomatoes indoors?

Tomato plants require a solid eight hours of daily sunlight. They also require an ambient temperature of approximately 70 degrees Fahrenheit or above. Choose a location on a windowsill or close to a screen door. If there’s concern about insufficient sunlight, utilizing specific grow lights or an indoor smart garden can be an effective solution.

Do tomatoes grow better in pots or in the ground?

Deciding whether it’s better to grow tomatoes in containers or in your garden? Tomatoes thrive in nutrient-rich, well-drained soil, making them well-suited to growing in containers, even in compact balcony spaces.

Opt for a 60-liter container for optimal growth. Ensure the plants are positioned in a sheltered area, protected from the wind, while receiving ample sunlight. It’s worth noting that tomatoes are heavy feeders. Therefore, maintaining fertile soil will contribute to their overall health and productivity no matter where they’re grown.

Final Words on How to Grow Tomatoes Indoors with Lights

Growing tomatoes indoors is a challenge, but with the right information and how-to’s, you can make it happen. Whether you’re growing cherry tomato plants or larger varieties, this article has all of the best tips on how to grow tomatoes indoors with lights.

Happy growing!

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About the Author

Elle Reed is a passionate gardener and advocate for teaching beginner gardeners how to grow their own food. Elle’s mission is to inspire and empower people to get back to basics, grow their own produce, and embrace a sustainable lifestyle. “Whether it’s a few herb pots in an apartment, a potager or a full garden plot, we can all ‘start somewhere’ to grow our own food, and in doing so, provide healthier food for ourselves and those we love”.

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