How to Grow Tomatoes Indoors with Lights | Top 10 Tips

While most plants often thrive outdoors, you can quickly learn how to grow tomatoes indoors with lights. Indoor gardening will enable you to maintain a regular supply of fresh, juicy, and nutritious vegetables throughout the year. However, growing vegetables indoors with LED lights requires specific conditions and considerations to observe for success. That’s why you must learn how to grow tomatoes indoors with lights before starting.

So, how can you grow tomatoes indoors with LED lights? This article explains how to grow tomatoes indoors with lights, including clear guidelines and tips to help you raise strong and healthy and eventually harvest nutritious tomatoes. 

How to Grow Tomatoes Indoors with Lights: 10 Key Guidelines 

The first question that usually comes to mind when planning indoor gardening is, can you grow tomatoes indoors with grow lights? Although growing tomatoes indoors with grow lights might seem like a simple feat to seasoned growers, it may be different for beginners. However, Gardenterprise wants to simplify it by explains how to grow tomatoes indoors with lights. Here are the critical guidelines for growing tomatoes indoors for beginners. 

Choosing the Right Tomato Seeds 

Start by learning how to grow tomatoes indoors with lights by choosing the right seeds for tomatoes. Many options exist, which is why it is challenging. However, consider a few things to buy the right tomato seeds. For instance, consider a variety of disease-resistant tomato seeds. Also, decide on whether to grow bush tomatoes or vining tomatoes. 

Bush or determinate tomatoes can only grow to a certain height, while indeterminate or vining tomatoes can grow as tall as the space allows. Nonetheless, it is advisable to choose determinate tomato varieties because they are easier to plant and maintain indoors with lights. 

Also, choose tomato seed varieties that can thrive well in containers. Tomato plants usually have deep roots, so choosing types that work well in containers will give you an easier time if you need to move them around whenever they become too large for the current containers. 

Tiny Tim, Yellow Pear, and Gardener’s Delight are some of the common tomato varieties in the market. However, you should go for types labeled ‘patio’ or ‘bush.’ Those are relatively small in size and compact to thrive well in containers. The best tomatoes to grow indoors include Bush Early Girl, Patio Choice Yellow, Atlas, and Tumbler. 

The variety you choose will influence your gardening and harvest. That’s why it’s a vital aspect to note when learning how to grow tomatoes indoors with lights.

Identifying the Right Soil 

Also, it’s crucial to know how to pick suitable potting soil besides knowing the grow lights tomatoes indoors requirements. The best soil for growing tomatoes indoors should be manageable. Also, consider a soil type that has essential nutrients and proper drainage. That’s because growing tomatoes indoors with lights requires soil that can stay moist longer. You can buy the right soil mixes from garden centers and retail stores online and offline. Besides, you may also need a potting mix for the soil you will use to grow tomatoes with light indoors. 

Indoor Tomato Light Requirements 

One of the questions you will need to ask when growing tomatoes indoors is how much light does a tomato plant need indoors? Growing tomatoes indoors means they will not have access to adequate natural light, so you must have proper plans to ensure that the plants have enough light for photosynthesis. While various options for grow lights for tomatoes exist, you should choose full spectrum LED grow lights when learning how to grow tomatoes indoors with lights. 

Full spectrum LED tomatoes indoor grow lights imitate natural light, ensuring your plants have adequate light for different phases of growth and development. Cool-colored grow lights with 6500k output encourage and stimulate indoor plants’ germination and leafing processes. In contrast, warm-colored grow lights with about 2700k are ideal for promoting flowering and fruiting in indoor tomatoes. 

Nonetheless, experts recommend a combination of warm and cool indoor tomato light for optimal growth. LEDs such as Aero Garden LED lamps are the best lights to grow tomatoes indoors. High-Pressure Sodium (HPS) lights can also work when you know how to grow tomatoes indoors with lights. However, HPS lights produce a lot of heat that could quickly burn your plants. 

Whether you choose professional or DIY lights for tomatoes, always ensure they can meet the needs of your plants. And this is vital when learning how to grow tomatoes indoors with lights since there are specific grow lights for tomatoes. However, you can also find versatile lamps that work well with several vegetable varieties and flowers. 

Watering Indoor Tomatoes 

Learning how to grow tomatoes with grow lights indoors also requires you to know the recommended watering cycles for tomato plants. Unlike tomatoes grown outdoors, indoor tomato plants need more frequent watering. You should check the plants’ daily water needs by touching the soil. Wait until the next day to water the plants if the soil is moist. 

You should water the plants until it flows out of the drainage holes if the soil is dry. However, moderate watering ensures the plants stay moist and not wet. Remember, too much water can harm your plants, encouraging root rot. A pot saucer or tray can help you reduce the risks of water logging by trapping excess water. 

Using soil and coir mixture can also help retain moisture to keep your plants healthy. A coir mixture will make the soil less compact than traditional soil, hence, better moisture retention. Use a moisture meter to test the plants and water appropriately. 

Temperature and Placement of Tomato Plants Indoors 

Another thing to consider when learning how to grow tomatoes indoors with lights is temperature requirement. Tomatoes usually thrive in warmer temperatures that may not be available indoors. So, learning how to grow tomatoes indoors with grow lights also means you should know how to maintain the best temperatures for your plants. Growing tomatoes indoors requires keeping the temperatures in the range of 70 to 80 degrees F. You should also avoid placing the plants next to cold windows or vents. 

Tomato plants love the sun, and you should place them in the brightest areas in your home, such as sunrooms or patios. If that is not possible, you should expose the plants to LED lights daily. You may be wondering how much light do I need to grow tomatoes indoors. The recommended tomato grow light hours is about 6 hours per day. 

Using Fertilizers 

Also, master fertilizer use when learning how to grow tomatoes indoors with lights. While you need nutritious soils to grow tomatoes indoors, regular fertilization is essential to ensuring healthy plants and bountiful harvests. That’s because the frequent watering of container-grown plants usually removes valuable nutrients from the soil, and you must replenish them to keep your tomatoes thriving and healthy. You should mix a slow-release pelleted plant food into the potting mix during planting and add pellets at intervals indicated on the package. Alternatively, you can also use a water-soluble fertilizer solution weekly. 


Pollination is also an essential aspect of how to grow tomatoes indoors with lights. Unlike outdoor gardens, pollination can be highly challenging in indoor environments. However, you can still facilitate the process with so much ease. Indoor tomatoes do not have access to bees or wind to pollinate. Thus, you do it by hand. 

Gently shake the plants daily to mimic the wind movements when they bloom. You can also facilitate pollination by gently uplifting pollen from mature flowers and brushing them onto young plants with a soft brush or cotton bud. Oscillating fans can also deliver the same results by creating a gentle artificial breeze to stimulate pollination. 

Technological advancements have seen the introduction of various artificial pollination products, such as the Be the Bee Pollinators that you can also use. It mimics a bee’s vibration, helping spread pollen amongst your plants. Therefore, figure out whether such technology is ideal for you when learning how to grow tomatoes indoors with lights.

Heat Requirements for Indoor Tomatoes 

Using grow lights for tomato seedlings ensures that your plants have adequate light, but they also need heat to speed up the germination process. Experts recommend setting your seed trays or containers on top of a gentle heat source such as a low-heat radiator, heat mat, or refrigerator. A few degrees of heat will hasten the germination of your tomato seeds, enabling you to start harvesting sooner. 

Transplanting and Support 

Tomatoes can quickly outgrow the containers used to plant them under optimal conditions. That means you should also know when to transplant your seedlings as a vital aspect to master when learning how to grow tomatoes indoors with lights. Experts recommend transferring tomatoes to larger containers whenever they reach 6 inches tall and have several leaves. The ideal container should be at least 20 inches deep. Remember, a larger container will give your plants more room to expand their roots. Therefore, have this in mind when learning how to grow tomatoes indoors with lights.

The containers you use to transplant the seedlings should also have proper drainage holes at the bottom to prevent waterlogging. Although the soil from the old containers may still contain nutrients, filling the new containers with fresh potting mix is also advisable. 

Tomatoes usually require support as they grow to handle the additional weight from bushy leaves and fruits. Sturdy supports such as tomato stakes and cages can be effective in that role. However, the cage’s top should remain open when using grow lights for tomatoes to ensure better access to light. You can also use strings and wires for support if you are growing vine tomato varieties. Ensuring proper support is essential and you should master it when learning how to grow tomatoes indoors with lights.

Harvesting and Post-Harvest Practices 

Will tomatoes ripen under grow lights? Yes, tomatoes can thrive and ripen under grow lights if you maintain the ideal cultural practices and conditions discussed above. A vital thing to know when learning how to grow tomatoes indoors with lights is that tomatoes grown indoors generally take about 80 to 85 days to mature. Be patient but harvest the tomatoes as soon as they feel soft and look ripe. Also, exercise great care when removing the tomato fruits to avoid damaging the foliage. 

Understanding how to grow tomatoes with grow lights indoors also requires knowledge about the best post-harvesting practices. Pinching back new growth can enable the plants to produce more fruits after the first harvest. To promote further flowering and fruit production, you can also treat tomatoes with plant hormones such as cytokinin. Knowing the best products for your garden is also a vital aspect of learning how to grow tomatoes indoors with lights.

Parting Shot

Growing healthy and nutritious tomatoes indoors with lights can be challenging, especially for beginner growers. However, accurate information and guidance on how to grow tomatoes indoors with lights can make all the difference. This article has provided the best tips on how to grow tomatoes indoors with lights. And by following these tips, you can avoid the common mistakes gardeners make and ensure bountiful harvests.  


Can you grow tomatoes indoors with grow lights?

Yes, you can grow tomatoes with lights indoors. However, you must choose suitable grow lights for tomatoes and observe proper cultural practices for indoor gardening, such as the ideal watering cycles, temperatures, heat requirements, fertilization, and pollination. 

What is the best light for growing tomatoes indoors?

A full spectrum LED grow light is the best option for those who need to learn how to grow tomatoes indoors with lights. Please choose versatile grow lights with dimmers that will enable you to regulate the proper light requirements for your tomatoes at different growth phases. Consider LED grow lights that produce warm and cool lights for optimal growth. 

How many hours of light do tomatoes need indoors?

Tomatoes grown indoors generally require light exposure of at least 6 hours per day. However, eight or more hours of quality light daily can deliver the best results with bountiful harvests. 

Can tomatoes grow in 24-hours light?

So far, scientists have established a gene in wild tomatoes that can enable the plants to grow in 24 hours of natural and artificial light. However, all plants generally need a light-dark cycle for proper growth and development. Tomatoes can grow in 24-hour light, but you should regulate it, so they also have dark cycles. Besides, keeping the grow lights on 24 hours a day will also cost you more electricity bills. 

Which lighting is best for growing tomatoes indoors?

Various lighting options exist for growing tomatoes indoors. However, full-spectrum LED lighting is the best because it provides the ideal wavelengths of light that tomatoes need to thrive indoors. LEDs also emit less heat, which enables them not to burn your plants. 

Henry Mugambi

Henry Mugambi

Take a look at this guy. He's almost in his 40s, but he looks like he could be in his 20s. That's because he's a gardener—and a damn good one, too. He's been gardening since he was a little kid, and he loves nothing more than sharing his tips with others. He started blogging a few years ago, and his blog has since become a go-to source for gardening information. His audience trusts him because he knows his stuff, and he always offers sound advice that helps people get the most out of their gardens.

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