Craving the taste of a fresh, homegrown tomato in the middle of winter? Tired of store-bought greens that barely last a few days? If outdoor gardening feels overwhelming, there’s a simple solution—gardening indoors with lights. With the right setup, you can enjoy vibrant, nutrient-rich produce year-round, no matter the season. Let’s explore how easy and rewarding it can be!
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Making a small investment in a good grow light can make a world of difference in what you can accomplish as an indoor gardener.
While many people are familiar with what a shop light does for seed starting in the spring, we consistently talk to people who are not familiar with what today’s advanced LED grow lights can bring to the table for an indoor gardener. Shop lights and even many of the LED grow lights available on Amazon simply fall short of offering optimal light levels for plants to fully mature, e.g., spinach, herbs and tomatoes.
For this article on indoor gardening, we are primarily focusing on growing food or edible plants, but indoor gardening can encompass any plants that someone wants to enjoy year round – and the same statement holds true – that a good quality grow light makes a difference in how well plants respond.
The Kratky Method: A Soil-Free Solution for Gardening Indoors with Lights
Combine a good grow light with a mind-blowingly simple method called the Kratky Method, (aka, passive hydroponics), and you will wonder why everyone hasn’t become an indoor gardener. It’s crazy how easy this is, and it can easily pay for itself in a short period of time with the savings on herb and spinach prices alone.
So some people have taken the plunge and purchased AeroGarden-type setups or Tower Garden systems because they want to experience the benefits of indoor gardening – and these systems can work out well. However, we hear many people find them either limiting or complicated to work with, and once they see the Kratky method, they realize they can do so much more with fewer resources. Another issue with these setups is the lighting is rarely up to the job of growing the types of plants that make a stellar indoor garden.
Very simply, the Kratky method is a soil-less way of growing in mediums such as clay pellets, rock wool, or coco-coir and vermiculite. At our home, we discovered this method because we started to have gnats showing up in great numbers when we used potting mix to grow indoors. Once we learned the method we said this is the only way to go and now we have taught thousands of people how to do this and they are simply delighted with how easy it is. The Happy Leaf LED YouTube channel is a great place to see step by step how we plant seeds and grow many varieties of food – even eggplants or edible flowers.
Let’s quickly talk about microgreens as well.
These little beauties are really superstars for indoor gardening because they pack a lot of flavor and nutrition into a very adaptable plant that can be added to soups, sandwiches, sauces, pizza, tacos, and to garnish just about anything! Talk about bang for your buck! A tray of microgreens that can be grown in 7 days can sell for as much as $25 at a farmer’s market using less than $1 in seeds per tray. Each variety of microgreen has its own unique flavor, be it broccoli, kale, sunflower, peas, radish, arugula, turnip, mustard green, etc. The flavors are quite vibrant and the nutritional punch is formidable. The USDA states that microgreens have five times the nutritional content of their mature counterparts.
What Are the Best Plants to Grow Indoors with Lights?
It’s possible to grow just about anything indoors if you have the patience, space and, of course, good light. The best things to start with are either lettuces, basil or your favorite herb, or microgreens. Personally, we love the spinach we grow indoors and think we’d miss that the most if we didn’t grow it all the time.
We continue to experiment with seed varieties to find the flavors we like and types of plants that are best suited to indoor gardening. For example, we recommend only choosing determinant tomato plants so the plant stays relatively compact. We also recommend working with cherry tomatoes or tomato varieties that are small to medium sized and not trying to grow the beefsteak types of tomatoes.
As for lettuce we favor the varieties mascara, black seeded Simpson, and crisp mint. We also love tender baby arugula.
Kale, don’t forget Kale! Lacinato is our personal favorite.
With spinach, we primarily grow the Corvair variety but we also like Bloomsdale Longstanding. Spinach does best in a mix of 70% coco coir and 30% vermiculite versus the clay pebbles that we grow lettuce and herbs in typically. We have decided to keep 4-6 14” round containers of spinach going at intervals so we can harvest it very regularly.
When choosing plants that flower, you want to go for seeds that are developed for container gardening because these plants are more likely to be compact. With these tomato varieties we haven’t had to worry about pollinating them ourselves:
Eggplants and zucchini- can be grown but you will need to hand pollinate them.
Choose Your Grow Light Wisely
Hop on Amazon and you can easily be overwhelmed by the sheer number of grow light options.
There are many misconceptions about grow lights, so first let us highlight some of these issues:
First of all, our human eye simply cannot accurately determine the quality of an LED grow light. Simply being bright tells us nothing. Nor does seeing a red or blue cast from a light. Today, any grow light that still has a strong “burple” appearance is giving itself away as having outdated LEDs.
Similarly, just because a light is longer doesn’t mean it will take care of a bigger grow area space. In this case, the 33” wide light has a wider beam angle and more energy and would do a more effective job of covering a 4 ft wide 18” deep shelf.
Many of the lower priced LED grow lights found on Amazon primarily rely on using white LEDS or outdated chip on board technology. These lights are built in extremely large quantities which results in a glut of older technology that sits in inventory until it is sold.
Grow lights with fans integrated into them definitely look serious. In truth, most grow lights that cost under $500 a unit with a fan are very likely using outdated technology
Also, a high quantity of LEDs doesn’t necessarily translate into a more powerful grow light.
The term “full spectrum” sounds good as well, but there are still wide discrepancies in the results we see in various full spectrum grow lights.
Watts, kelvin or lumens are commonly used to describe a grow light’s effectiveness. Unfortunately, these terms are inaccurate at a minimum and are more often misleading. The most accurate measurement for understanding what a grow light can do is the PAR measurement. PAR stands for photosynthetic active radiation. Don’t worry though. It doesn’t have to get any more complicated to understand what you need to know about grow lights.
Just know that if you are able to get a PAR statistic for the light, you are already able to make a better decision. In very general terms, to grow the widest variety of plants to full maturity, including flowering, you need to have a PAR measurement over 200 micromoles per square meter per second.
Even if you can’t find or easily understand what the PAR measurements are for a grow light, the instructions or specifications should at least tell you how much area is covered and what type of growth is supported. A key differentiator is whether the light supports fruiting and flowering plants.
A Little More About PAR
On a basic level, PAR represents how plants see light, which is entirely different than how humans see light. PAR energy is measured in the number of photons per square meter per second.
PAR measurements are primarily expressed in micromoles per square meter per second, and can get a little confusing to understand especially since there are a number of different choices to express this number including the scientific symbols. But as we mentioned, you don’t really need to have a deep understanding behind this measurement or even a PAR meter.
Typically, professional grow lights often provide a PAR Map to explain exactly what PAR measurements are reading relative to the coverage area and the distance of the light.
When choosing a grow light, it is important to know what you will be growing so you can be sure to get enough PAR energy from the light.
Here is a basic guide:
Microgreens and seed starting need 100 to 200 PAR
Vegetative plants need 200 – 400 PAR
Fruiting plants need 300 – 600 PAR
The Power of PAR
See the power of PAR energy in action, watch The Grow Light Lettuce Challenge on Happy Leaf LED’s YouTube channel!
Better quality grow light spec sheets will provide an “efficacy” measurement. The efficacy is measuring how much useful light is emitted for plant growth for the amount of energy being used. The higher the number, the better.
At this time, a good number to see is 2.5 (μmol/J)
Many consumer grade grow lights are 2.0 (μmol/J) or less or they don’t even mention their values.
A spectral graph can also be very informative as it will specify the balance of red, blue and green light that is used for that specific light. Research at leading universities has confirmed there is an ideal ratio of red, to blue to green light to achieve maximum plant growth. The ideal ratio is 70% red, 10% blue, and 20% green light.
These images are from research done by Professor Erik Runkle at Michigan State, comparing the results of the same intensity of light by varying the red, blue, green colors.
The difference in delivering the optimal type of light to plants shows up not only in the size of the plant, but also the nutritional value, the taste, and the overall health of the plant.
A very noticeable impact with high quality LED grow lights is how quickly growth is seen.
Start Growing Indoors Today
With the right grow lights and techniques, indoor gardening becomes simple, rewarding, and cost-effective. Whether you’re a beginner or an experienced gardener, Happy Leaf LED lights provide the tools you need to grow with confidence.
Ready to begin your indoor gardening journey?
Explore Happy Leaf’s LED grow lights and start growing smarter today!
Growing tomatoes indoors with LED grow lights lets you enjoy fresh, homegrown tomatoes year-round, even if you don’t have outdoor space or natural sunlight. At the Happy Leaf workshop, we are growing tomatoes indoors in a windowless room using our powerful grow lights that mimic sunlight—so you can do the same!
This indoor gardening method is perfect for apartment dwellers or anyone wanting fresh tomatoes during colder months. With a simple indoor setup, you can plant, nurture, and harvest tomatoes in your kitchen, living room, or even a closet.
Growing tomatoes indoors may seem daunting at first, but with the right supplies and setup, you can enjoy an abundant harvest. After testing various tomato varieties, growing mediums, and nutrients, we’ve developed a proven system. Today, we’ll guide you step-by-step to skip the frustration and enjoy growing tomatoes indoors successfully.
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How To Grow Tomatoes Indoors with LED Grow Lights -Part 1 (VIDEO)
We’re going to dive straight into the step-by-step guide. Keep reading for details on why each recommended item is important and answers to common questions about indoor tomato gardening.
What You’ll Need
Before you start growing tomatoes indoors, gather these essential supplies:
Compact variety tomato seeds (see below for more details)
Tomato cage or support structure (see below for more details)
Growing medium – 50/50 mix of coconut coir and vermiculite (see below for more details)
Nutrients/Fertilizer: We recommend Maxigro for seed starting and Maxibloom for flowering and fruiting (see below for more details).
Step 1: Prepare Indoor Garden Space – Using Grow Lights for Tomatoes
Your grow light is the key to growing tomatoes indoors successfully. Set up your space before planting the seeds. You can start the seeds in the same container you will grow them in.
Instructions:
Choose Your Space: Select a location with enough room for both your plants and grow light, such as a wire baker’s rack, a closet, or even a corner of your living room. The optimal indoor temperature for tomatoes to grow is between 65° – 80° Fahrenheit, which aligns with the average temperatures in most U.S. homes.
Install the Grow Light for tomatoes: Position the Happy Leaf Procyon 2.0 LED grow light 12-18 inches above your plants. This light provides the ideal intensity for indoor tomato growth. As the tomato plant grows, adjust the height of the light using the strings and hardware included with your grow light to maintain the optimal distance.
Set a Timer: Tomatoes need 16-18 hours of light per day, so use a timer to automate the process. Ensure the grow light schedule stays consistent, as this is essential for proper plant development. While seeds don’t need light to germinate, setting up your grow light and timer at this stage saves you from needing to remember to set them up once the seeds begin to sprout.
Left: Suggested structures for growing indoors. Right: Grow light hanging distance from plant.
Tip: Avoid placing your tomato setup near vents or in unfinished basements where temperatures may fluctuate or drop too low.
Step 2: Plant the Tomato Seeds
Starting from seeds ensures your plants adapt well to indoor conditions right from the start. This is the time to mix the growing medium that will be used from start to finish.
Instructions:
Prepare the Growing Medium: Expand the coco coir brick according to package directions. In a large container, mix equal parts coconut coir and vermiculite. This mixture provides excellent drainage and root aeration.
Fill the Container: Add the growing medium to the container, filling it nearly to the top but leaving about 3 inches of space unfilled. Gently press down the mix to create a firm, even surface.
Plant the Seeds: Use your finger to make indentations in the growing medium of about ¼ inch deep in the soil. Place one seed in each hole and cover lightly with soil.
Watering: Generously water the seeds from the top for the initial watering. After this, only water the plant using the reservoir located near the bottom of the container.
Place Under Grow Light: Once planted, position the container under the Procyon 2.0 grow light, keeping it on for 16-18 hours per day. While seeds don’t need light to germinate, setting up your grow light and timer at this stage saves you from needing to remember to set them up once the seeds begin to sprout.
Step 3: Select / Thin Your Seedlings
After 3-4 weeks, your tomato seedlings should be 4-5 inches tall. We recommend growing only one tomato plant per container, so you can either transplant the extra tomato plants into another container or simply thin out the seedlings by choosing the strongest looking seedling.
Instructions:
We recommend growing only one tomato plant per container, so you can either transplant the extra tomato plants into another container or simply thin out the seedlings by choosing the strongest looking seedling. In the example below we would keep the plant located on the right as it is taller and healthier looking.
Step 4: Care and Maintenance
Proper care will ensure that your indoor tomato plants thrive and produce a bountiful harvest.
Instructions:
Watering Schedule: As mentioned above, start with a generous watering from the top, then switch to providing water only through the container’s self-watering reservoir. Check the reservoir every few days, adding nutrient-rich water as needed. Once the plant begins blooming, it may require more frequent watering.
Nutrients: Fertilize your plants with Maxigro 10-5-14 during the early growth stages. Once the plant starts flowering, switch to MaxiBloom to promote fruit production. We recommend this brand as they are one part and don’t require measuring different quantities. See below for more information.
Pruning: Remove any lower leaves that aren’t producing fruit. Pruning encourages better airflow and reduces the risk of disease.
Pollination: Another advantage of growing tomatoes indoors is that they are self-pollinating, so you don’t need to worry about manually brushing the flowers or shaking the plant, though doing so won’t harm it. If desired, you can also use a small fan to promote airflow.
Common Problems and How to Solve Them
Even with a great indoor setup, some issues may arise, but they’re easy to overcome with the right knowledge.
Common Issues:
Yellowing Leaves: Indicates nutrient deficiencies (typically nitrogen or magnesium). Make sure you are following the directions on the nutrient package.
Curling Leaves: Often due to overwatering, excess heat, or lack of pruning. Using a self watering container will help avoid this issue. If not using a self-watering container, adjust your watering schedule and ensure proper ventilation.
Pests: While rare indoors, aphids and spider mites can appear. Use a mixture of water and dish soap or neem oil to wipe down the leaves.
Step 5: Harvesting Your Indoor Tomatoes
In about 60-80 days, you’ll start to see ripe tomatoes forming on your plants. Here’s how to know when they’re ready and how to harvest them.
Instructions:
Check for Ripeness: Look for full, vibrant colors depending on the variety (red, orange, or yellow). The tomatoes should be slightly soft to the touch.
Harvest Gently: Twist the ripe tomato off the vine or use scissors to cut the fruit. Be careful not to pull too hard, as this can damage the plant
Continue Producing: Your indoor tomato plant can continue producing fruit for months with proper care, so be sure to regularly water and fertilize it after each harvest.
Tip: If you’re not ready to eat your tomatoes right away, store them at room temperature to ripen further.
Step 6: Starting A New Crop
When growing tomatoes indoors, it’s important to recognize when your plants have reached the end of their productive life. Over time, the plants will stop producing fruit and begin to look dry and scraggly—this is your cue to start a new crop.
Instructions:
Remove Organic Matter: Pull out all roots and leftover plant material from the growing medium.
Dry It Out: Allow the coco coir to dry completely before reusing it. Seeds tend to germinate better in dry coco coir.
If you experienced frequent issues with disease or pests during your grow, it’s a good idea to wash and sanitize your container before starting your next grow cycle.
Choosing the Best Supplies for Indoor Tomato Gardening
Best Indoor Tomato Varieties
Growing tomatoes indoors can be rewarding, but not all varieties are suitable, especially for beginners. To achieve the best results in limited space, consider choosing compact or dwarf varieties. Here are our top picks :
Tiny Tim: Compact and ideal for small spaces, producing small, sweet tomatoes.
Totem: This dwarf variety thrives in containers and small spaces, making it easy to manage.
Red Robin: A high-yielding variety that offers small, flavorful tomatoes.
Yes, you can grow full-size tomatoes indoors, but they come with challenges such as needing significant support due to their size and long vines. For easier management and better productivity, compact varieties are recommended.
Should I Start from Seeds or Seedlings?
Starting from seeds is the best option. At Happy Leaf, we always begin our tomatoes from seed to provide consistent lighting conditions, reducing stress during the transition to indoor environments.
The Best Grow Lights for Tomatoes
For anyone interested in having the best grow lights for tomatoes, we recommend the Happy Leaf LED Procyon 2.0. This LED grow light is designed to mimic sunlight and covers the full spectrum needed for both vegetative and flowering stages, making it energy-efficient and perfect for indoor setups.
Tomatoes thrive with 16-18 hours of light daily. Tomatoes need a PAR (photosynthetic active radiation) reading of 400 or more to produce flower and fruit. PAR is the portion of the light spectrum used by plants for photosynthesis. Learn more about PAR and other important grow light metrics by reading our blog post, What You Really Need to Know About Grow Lights.
Do I have to use a timer?
You can have the ideal setup and the most efficient LED grow light, but it’s crucial to have a proper lighting schedule in place. While a timer isn’t technically necessary, it streamlines your growing process and simplifies your life by eliminating the need to remember to turn your grow light on and off.
How much does it cost to run?
Running the 17″ Happy Leaf LED Procyon 2.0 for 16 hours a day will only cost you about 5¢ a day!
The Best Containers for Indoor Tomato Growing
Selecting the appropriate container is crucial for supporting plant growth and maintaining moisture. We recommend the 14″ self-watering pots from Bloem or this Walmart brand These pots have built-in reservoirs to provide a steady supply of nutrient-rich water.
Left : 14″ Bloem container Right: 14″ Mainstays Container
Plant Supports and Tomato Cages
Tomato cages can also be a great option and can be found online or at many big box stores. Make sure that the dimensions of the tomato cage are an appropriate fit for the size of container you choose.
Wire bakers rack or shelving unit – Big box stores, online, thrift stores
Do-it-yourself PVC pipe tomato cage – see below to download instructions and make yourself!
Get creative!
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Optimal Growing Medium
For the best results, we recommend using a 50/50 mix of coconut coir and vermiculite:
Coconut Coir: Readily available at most garden centers, big box stores and online. Coconut coir or coco coir, comes in bricks that expand with water, making it affordable and space-efficient option for growing tomatoes indoors.
Vermiculite: Readily available at most garden centers, big box stores and online. Vermiculite helps aerate the growing medium and promotes good drainage and overall health for the plant.
You can substitute perlite for vermiculite. While traditional soil can also be used, the coco coir and vermiculite mix reduces pests, weight, and enhances growth conditions for indoor tomatoes.
Nutrients
We recommend using the MaxiGro + MaxiBloom system from General Hydroponics as they are very straightforward and don’t require a lot of mixing or multiple parts.
Masterblend is another great option for indoor tomato gardening, but requires a little more attention to detail when measuring the 2-part system.
FAQs About Growing Tomatoes Indoors
How long does it take to grow tomatoes indoors with LED lights? On average, it takes 60-80 days from seed to harvest, depending on the variety.
What if I don’t use a self-watering container? If not using a self-watering pot -Allow the top inch of soil to dry out between watering. Overwatering can lead to root rot, while underwatering can cause fruit to split.
Can a fluorescent light grow tomatoes? No, fluorescent lights do not produce enough photosynthetically active radiation (PAR) or proper light spectrum to allow tomato plants to reach the flowering stage.
How often should I water my tomato plants? Water deeply but let the top inch of soil dry out between watering. Self-watering containers help maintain proper moisture levels.
Do I need to pollinate indoor tomatoes? No, tomatoes are self-pollinating.
Do tomatoes ripen after being picked? Yes, tomatoes continue to ripen off the vine if picked at the mature green stage or later. Store them at room temperature for best results.
How can I tell if I’m overwatering my tomatoes? Signs of overwatering include yellowing leaves, slow growth, and waterlogged soil.
Can you suggest a plant stand for your 33-inch light?Tomato Trellis
Do I need a grow tent? No, as long as your temperature in your grow area is between 65° – 80°. If you choose to grow in an area that is outside of that range, a grow tent may be a good option.
What are the green buckets for? We like to set the pots up off the floor a little ways- it’s easier to put the water spout into the watering lip of the pot. The buckets also serve as a way to catch a little overflow water as well.
Every time you water, do you only use nutrient water? Or do you water some days and nutrient water other days? Nutrient water should be used whenever watering your tomato plant
Conclusion
Growing tomatoes indoors with LED grow lights is simple and rewarding. With the right setup and care, you can enjoy fresh tomatoes year-round, no matter where you live.
Hello! I’m Vic, the owner and chief grower at Happy Leaf LED. Today, I’m excited to share the amazing benefits of growing microgreens and provide step-by-step guidance on how to grow microgreens without soil in your indoor garden. I’ll guide you through everything you need to know—from materials needed and their purpose, how to get started and what you can expect when growing these nutrient-packed greens without soil using our Happy Leaf LED grow lights. Let’s dive in.
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How To Grow Microgreens Without Soil (VIDEO)
What Are Microgreens?
Microgreens are herbs and vegetables harvested within one to three weeks after planting, when the “true leaves” have formed. We can think of microgreens as immature herbs and vegetables.
Microgreen seeds and regular seeds are botanically the same, coming from the same parent plant and having the same genetic makeup. They differ in the way they are grown. Microgreen seeds are planted close to one another and harvested about 5 to 14 days after they are planted. A mature plant would take more time to grow using only a few seeds.
How do I know when they are ready to harvest?
Microgreens are typically ready to harvest within 1-3 weeks of growth, depending on the specific variety you are cultivating. For example, fast-growing varieties like radishes and broccoli can often be harvested in as little as 7-10 days, while slower-growing types such as basil or cilantro might take closer to three weeks.
Microgreens are harvested soon after the first true leaves take shape. The true leaves are the second set of leaves that appear during growth. Herbs and vegetables start life with one or more, commonly, two embryonic leaves. They’re called cotyledon leaves.
Several days after these tiny delicate leaves pop through the surface of the soil, another set of leaves form. They are considered the first “true leaves”. When you eat microgreens, you will be dining on three components, the stems, the cotyledons, and the true leaves.
The peak flavor and nutritional value of microgreens are usually achieved when they reach a height of 1-3 inches. At this stage, the tiny plants are packed with intense flavors and a high concentration of vitamins, minerals, and antioxidants. Harvesting them at this optimal height ensures you get the best taste and nutritional benefits in every bite.
Are microgreens the same as sprouts?
No, but they are close relatives. Sprouts, microgreens, and baby greens form a continuum from seed to mature plant.
Sprouts are veggies harvested earlier in their life cycle, notably about 3 to 4 days after sprouting. They are tiny plants with cotyledon seeds. Microgreens are typically harvested 7 to 14 days after the first true leaves form.
Do microgreens regrow?
While microgreens don’t technically “regrow” after harvesting, you can still get a second, smaller harvest from the same tray. When you cut your microgreens at the root, you create space for seeds that weren’t getting enough light to finally sprout, and for smaller microgreens to stretch out and thrive. This secondary growth won’t be as abundant as the first, but it’s a great way to maximize your yield and enjoy an extra harvest from the same planting.
How long will fresh microgreens last after they are harvested?
Freshly harvested microgreens typically remain fresh in the refrigerator for about 10 to 14 days, though this can vary by type. Hardier varieties, such as sunflower and pea shoots, can stay fresh for up to three weeks, while more delicate greens like basil might only last around five days. For optimal flavor and nutritional value, it’s best to harvest microgreens as needed. If you need to store them, keep them dry and in an airtight container with a paper towel to extend their shelf life.
Are all veggies and herbs suitable for microgreen growing?
Most herbs and vegetable seeds can be grown as microgreens hydroponically under LED grow lights. That said, some veggies work better than others. Plants in the Brassica family, such as kale, broccoli, red cabbage, and kohlrabi, for example, are microgreen superstars. They germinate well, grow quickly, and grow reliably. Other superstars are radishes, Swiss chard, beets, and arugula. We recommend that you start with these high-performance microgreens.
Benefits of Microgreens
Out of all the things I grow at home and at the Happy Leaf workshop, microgreens come in as one of my favorites. I often recommend them for beginners as you can see your results quickly, even just 1 week in some cases. Learning how to grow microgreens without soil indoors offers numerous advantages that make it an appealing option for both novice and experienced gardeners. Here are some key benefits:
Diverse and wonderful flavor
Each variety of microgreen basically has its own unique flavor, be it broccoli, kale, sunflower, peas, etc. The flavors are quite vibrant. Arugula, cress, radish, turnip and mustard greens are especially spicy and are great additions to strongly flavored foods such as pizza or tacos.
Nutrient-rich superfood
Here’s a fact that might convert you to a microgreen connoisseur. Microgreens are more nutritious than full-grown veggies. According to the US Department of Agriculture, microgreens contain, on average, five times the nutritional content of their mature counterparts. Bear in mind, that’s an average. There are many exceptions. Red cabbage microgreens, for example, contain forty times more Vitamin C and six times more Vitamin E than mature red cabbage. We recommend that you start with these high-performance microgreens.
Cost-effective
Once you learn how to grow microgreens without soil at home, it will become obvious that it is an economical choice. A $25 bag of seeds can last up to a year or two if grown diligently. This means you can enjoy fresh, nutritious greens without constantly spending money at the grocery store. The initial investment in seeds and growing materials quickly pays off with the continuous harvests you can achieve. Note that at urban farmer’s markets, we have seen a small tray of microgreens sell for as much as $25!
Space-saving
One of the greatest advantages of growing microgreens is that they require very little space. They can be grown in small areas such as kitchen cabinets, basements, or closets with the help of efficient grow lights. This makes them an ideal option for urban dwellers or anyone with limited gardening space.
The Kratky Method : Hydroponic Growing Made Simple
The Kratky Method, also known as passive hydroponics , Kratky hydroponics or non-circulating hydroponics is our favorite technique for growing not only microgreens but also a variety of greens like lettuce, herbs, arugula, chard, and collard greens. Developed by Dr. Bernard Kratky, who was a professor at the University of Hawaii, this method offers an efficient and cost-effective approach to hydroponic gardening.
Source – College of Tropical Agriculture and Human Resources: Dr. Bernard Kratky
One key to the success of the Kratky Method is that plants grown in a nutrient-rich “water bath” are able to derive all the oxygen their roots need from the air space between the bottom of the tray and the water’s surface. This is a significant advantage compared to soil-based growing, where plants acquire their oxygen from air in tiny spaces between soil particles. Additionally, unlike active hydroponic systems that require electricity to pump air into the water to supply the roots with oxygen, the Kratky Method relies on natural aeration, making it simpler and more cost-effective.
So, why do we love the Kratky Method so much? First and foremost, it’s incredibly clean—no soil means no mess, which is particularly beneficial during the harvesting process. You don’t have to worry about spilling dirt everywhere, making it a hassle-free option.
Second, it significantly reduces the risk of pests. Since you’re not introducing organic matter like soil or peat moss, the possibility of bugs is greatly minimized. Third, it’s both economical and convenient. There’s no need to continually purchase bags of soil; you only need water, which is readily available in your home. It’s basically magic and it’s easy—what’s not to like?!
Why Grow My Microgreens Indoors vs Outdoors?
When it comes to growing microgreens, choosing an indoor hydroponic method over traditional indoor/outdoor soil-based methods offers several distinct advantages. Here are the key reasons to consider growing your microgreens indoors with the Kratky Method:
Cleanliness
One of the most significant benefits of growing microgreens without soil in water is the cleanliness it offers. Unlike soil-based growing, which can be messy and cumbersome, hydroponic growing eliminates the hassle of dealing with dirt. You won’t have to worry about spilling soil all over your kitchen or grow area, particularly during the harvesting process. This not only keeps your space tidier but also reduces the cleanup time, making the overall growing experience more enjoyable and less labor-intensive.
Reduced risk of pests
Growing microgreens hydroponically also significantly reduces the risk of pests. Soil and other organic matter, such as peat moss, can harbor a variety of insects and pests that might invade your growing area. By eliminating soil from the equation, you minimize the likelihood of dealing with unwanted bugs. This not only protects your microgreens from potential damage but also provides peace of mind knowing that your greens are growing in a controlled, pest-free environment.
Cost & convenience
Hydroponic growing is often more cost-effective and convenient compared to traditional soil-based methods. There’s no need to repeatedly purchase bags of soil, which can add up over time. Instead, all you need is water, which is readily available in your home. This makes hydroponic growing a more economical choice, especially for those who plan to grow microgreens continuously. Additionally, the convenience of simply turning on the faucet to water your plants cannot be overstated, streamlining the entire growing process.
What Do You Need to Grow Microgreens Without Soil?
While an initial investment is needed, many of the supplies required may already be in your home. Here, we will go over suggested materials and alternative options. We will be providing links, but we also encourage you to shop local when possible!
Microgreen trays:
We typically use these 8×10 inch trays with mesh bottoms for proper water drainage. Ensure that whatever tray you choose comes with a lid to retain moisture during the germination period.
Grow lights:
Happy Leaf offers a 17-inch and 33-inch Procyon 2.0 Full-Spectrum Grow Light. A 17-inch light can accommodate three trays, while a 33-inch light can grow up to six trays. For optimal growth, you will want to use a light with a PAR of 200 µmol/m²/s ( 20o micromoles per square meter per second). Happy Leaf lights are designed with ideal spectrums that provide optimal PAR for all growing stages, outperforming typical shop lights by giving the plants a sturdier stem as well as allowing them to grow even faster.
Timers : To streamline the process, we also recommend a timer for your grow light so you don’t have to try to remember to turn your light off and on. Happy Leaf carries these grow light timers, but a version of this can usually be found at many hardware and big box stores.
Even if your windows aren’t coated, winter presents its own challenges. With shorter days and often cloudy skies, it’s tough to give your plants the consistent, high-quality light they need. A few hours of weak sunlight each day just won’t cut it, especially for light-hungry microgreens. This is where a grow light becomes a game-changer.
Using a Happy Leaf LED grow light ensures that your microgreens get the exact amount of light they need, regardless of the season or window setup. You’re not just supplementing sunlight; you’re providing a perfectly controlled environment that optimizes growth. With a grow light, you can grow not only robust, healthy microgreens but also tomatoes and succulents in the comfort of your own home and all year round! .
Want to take a deep dive into the science behind grow lights? We’ve got you covered!
Nutrients:
MaxiGro Nutrients 10-5-14 by General Hydroponics is our tried and tested hydroponic nutrient of choice. Each 8X10 tray needs about a quart of water. With MaxiGro, you only need to use one teaspoon per gallon of water, making this an economical choice at about $0.02 per tray.
There are many nutrient choices out there that require multiple parts and complex mixing recipes. MaxiGro’s one step process removes that headache and provides great results.
*If you choose to try another nutrient, just make sure you get a “hydroponic nutrient blend.”
Microgreens come in all types of varieties, this diversity allows you to choose the flavors and nutrients that best suit your taste. One of our favorite places to buy microgreen seeds from is the American company Johnny’s Seeds. From my experience, Johnny’s has the largest selection of seed varieties, the option to buy in bulk or small sizes and the best prices.
Here are some of my personal favorites and great choices for beginners:
Red Russian Kale – Mild taste, fast growing, great in salads and omelets
Broccoli – Mild taste, fast growing, great in soups and sandwiches
Red Cabbage – Mild taste, fast growing, great in pastas and avocado toast
Daikon radish – Fast growing, spicy, great in sandwiches and pasta
Purple kohlrabi – Fast growing, looks and tastes great in salads
Happy Leaf loves supporting other USA-Made businesses, and we’ve had very successful growing experiences using their products. They provide so much detail in their descriptions making it easier to decide what microgreens to grow. Johnny’s Seeds online store to learn about flavor profiles and expected harvest times on a wide variety of microgreens.
Do I need to know anything special to grow seed mixtures?
If you want to experiment with mixtures, be careful to plant a mix of seeds that grow at comparable rates. Microgreens grow at different rates. Some plants, like kale and broccoli, grow faster than others such as beets and sunflowers.
Speaking of flavors…
7 Uncommon and Delicious Leafy Green Varieties to Grow In Your Indoor Salad Garden
How To Grow Microgreens Without Soil: Complete Step-By-Step Guide
Step 1: Gather supplies
Microgreen tray with lid
Grow light
Nutrients
Seeds
Water
Paper towel
Scissors
Timer (optional/recommended)
Step 2: Prepare the nutrient water
1 tsp per gallon when using MaxiGro, otherwise follow the directions on your nutrient package.
Step 3: Set up Your grow light
Hang your grow light 14”-18” from your microgreen tray.
Grow Light Schedule: Microgreens generally require 12 -16 hours of light per day. We schedule our lights to be on for 16 hours a day (7am – 11pm) and adjust them from there. We HIGHLY recommend using a timer for your grow light to streamline the process and ensure success. No need to try and remember to turn your light off and on. You can find a grow light timer in the Happy Leaf store as well as local hardware and big box stores.
Step 4: Place and prepare microgreen tray
Insert the top mesh tray with holes into the bottom tray without holes and place it on your shelf or growing area under your grow light before adding water to avoid spills.
Add your nutrient filled water to your microgreen tray until the water level just reaches the top of the mesh tray. You don’t want the seeds to be completely submerged in water.
Cut a paper towel to fit the bottom of the tray to prevent seeds from falling through and place it on top of the mesh.
Step 5: Sow the seeds
Spread the seeds evenly over the paper towel. Try to keep them about a seed-width apart from each other, but don’t stress over it too much. As long as they are not heavily clumped on one another they should be successful.
Step 6: Cover and germinate
Place the lid on the tray to retain moisture during the germination process. Once the seeds start to germinate (2-3 days) remove the lid for the remainder of the growing process. Although seeds do not require light for germination, it will not hurt the process and can be beneficial to have the grow lights on from the start so you don’t forget about turning them on after a few days.
Step 7: Growth and maintenance
After the seeds have germinated (2-3 days), remove the lid and allow the microgreens to grow under the lights . Watering is minimal during the first week to week and a half. As the microgreens mature, add nutrient water as needed without overfilling to ensure the roots get sufficient oxygen. As long as the roots are touching water, the microgreens will be able to absorb what they need.
How To Harvest Microgreens
Microgreens are typically ready to harvest within 5-14 days of growth and should be harvested once they reach a height of 1 to 3 inches , which is when they are most flavorful.
Harvest: Use scissors to cut the microgreens just above the root level. Leave the roots in the tray.
Second Harvest: While the cut microgreens will not regrow, any immature plants or seeds may continue to grow, allowing for a second, smaller harvest.
How to Clean and Reuse Supplies
After you have harvested your microgreens, it’s time to start a new grow, but first, let’s clean our supplies.
Remove all debris and plant residue from the trays. Rinse the tray under hot water and use dish soap and either a sponge, brush, or paper towel to scrub the trays and remove any leftover seeds, or roots. Rinse til clean and let your tray air dry.
We typically stop there, but if you’d like to sanitize your trays:
You can use one of the following methods:
Boil: Boil tray in water for 3 minutes.
Spray: Mix equal parts white vinegar and water in spray bottle and spray on tray. Rinse after 10-2- minutes.
Soak: Soak trays in 1 part hydrogen peroxide to 10 parts water for 10-20 minutes.
Rinse trays thoroughly with clean water and let dry before using.
And that’s pretty much it! You’re off and running and ready to start a new tray and you’ll want to show your friends and family how to grow microgreens without soil !
Can You Eat Microgreen Roots?
While microgreen roots are technically edible, we don’t recommend consuming them. In hydroponic systems, like the ones used with Happy Leaf LEDs, the roots remain exposed to water and nutrients rather than soil. However, even in these clean environments, roots can still be vulnerable to bacteria, mold, and other microorganisms that thrive in moisture-rich conditions. Consuming the roots could increase the risk of ingesting these contaminants.
The best part of the microgreen for consumption is the stems and leaves, which are packed with nutrients and vitamins. We recommend harvesting your microgreens by cutting just above the root line, ensuring you get the safest, most nutritious portion of the plant.
As for the roots, while they aren’t suited for consumption, they don’t have to go to waste. After harvesting, the leftover roots from your hydroponic grow can be composted or used as organic matter in your garden.
How to Use Microgreens [5 Free Recipes]
5 free microgreen recipes
Save time in the kitchen with these free recipes!
5 free microgreen recipes
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Microgreens are versatile and can be used in various dishes:
Salads: Add a handful to your salads for a nutritional boost
Garnishes: Use them to top off soups, sandwiches, and main dishes.
Smoothies: Blend them into your favorite smoothies for extra vitamins and minerals. Bonus, add some edible flowers for an aesthetic and delicious treat!
Common Issues and Solutions
Can I eat microgreens if they grow past 3 inches? Yes, you can eat microgreens even if they grow past 3 inches, but their texture and flavor may change. As microgreens grow taller, they start to resemble baby greens and can become tougher and less tender. The flavor might also become more intense or bitter, depending on the variety.
Wilting: Microgreens may wilt if they aren’t getting enough water or if they’re overwatered, leading to root rot. Proper watering is key to keeping them healthy. remember, don’t refill the water in the tray all the way, the top of the roots need to be able to reach the air.
Legginess: If the stems are long and spindly, your microgreens may be stretching for light, try lowering your grow light or placing something under your tray to raise the height. A distance of 14-18 inches is ideal for microgreens.
Slow Growth: If your microgreens are growing slower than expected, it could be due to stress from unfavorable conditions such as temperature, or an inadequate grow light schedule. Aim to run your grow light for 16-18 hours a day.
Mold or Fungal Growth: This can occur if there is too much moisture and poor air circulation. This is most likely due to filling your tray with too much nutrient water and not allowing air flow to the top of the roots of your microgreens, essentially “choking” the roots. As long as the roots are touching the water, they are getting what they need.
Urban Microgreen Farming
Urban farming is revolutionizing food production, and companies like Urban Greens – Minneapolis, MN, Closed Loop Farms – Chicago, IL and Contemporary Farmer Inc. – Chicago, IL are leading the way in modern food cultivation using Happy Leaf LED grow lights. Visit our commercial LED grow lighting page or watch some testimonial videos to learn more.
Pictured: Closed Loop Farms – Chicago, IL
Do you have an indoor growing operation or are thinking about starting one? Contact us today for a free grow light consultation.
Learning how to Grow microgreens without soil indoors is a simple and rewarding process that can provide a continuous supply of fresh, nutritious greens. Whether you’re a gardener, home cook or looking to start a small business, microgreens offer a versatile and profitable venture.
Growing spinach outdoors is often limited by the seasons, with the plants thriving in cool weather but struggling in the heat of summer or the chill of winter. However, by growing spinach in your indoor garden, you can enjoy fresh, homegrown spinach year-round, free from the challenges of pests, bolting, and weather extremes. In this guide, we’ll go over the benefits, methods and materials needed . You’ll also receive a step-by-step guide that will give you the confidence to grow a thriving crop of spinach in your home, no matter the season.
Growing spinach indoors offers a wealth of benefits:
Year-round availability: Harvest fresh spinach regardless of the season, enjoying its vibrant flavor and nutritional value.
Control over growing conditions: Optimize light, temperature, and nutrients for healthy, thriving spinach plants.
Reduced exposure to pests and diseases: Protect your spinach from outdoor threats and enjoy a cleaner, healthier harvest.
Convenience and space-efficiency: Grow indoors regardless of limited outdoor space, enjoying the satisfaction of homegrown spinach right at your fingertips.
Optimized for flavor and texture: Contrary to some expectations, food grown indoors can actually have a very appealing texture and flavor.
This guide specifically focuses on the use of Happy Leaf LED lights, renowned for their effectiveness in promoting healthy plant growth. Keep in mind that all grow lights are not the same. Happy Leaf LED lights provide the perfect environment for your indoor spinach to flourish.
Preparing for Indoor Spinach Cultivation
Choosing the right container is crucial for successful indoor spinach cultivation. Consider the following:
Size: Opt for a container that is at least 6 inches deep and 12 inches wide to accommodate root growth. Self-watering vegetable planter boxes are ideal.
Drainage: Ensure the container has drainage holes to prevent waterlogging.
Material: Choose a material like clay, plastic, or fabric that is porous and allows for air circulation.
Next, select a spinach variety that thrives indoors.
Popular choices include:
Space: A compact variety with short, upright leaves.
Happy Leaf LED grow lights:Select a grow light suitable for the size of your growing area. The 33” Procyon 2.0 is the perfect size for that vegetable planter box
Seeds: Purchase certified organic spinach seeds.
Timer: Automate the light cycle for consistent growth.
Setting Up the Growing Environment
Spinach prefers a cool environment with temperatures between 60 and 75°F. Typically our homes are within this range. Place your Happy Leaf LED lights approximately 12-18 inches above the container. Aim for 14-16 hours of light per day. We recommend using a programmable timer so you don’t have to worry about turning your light off and on.
Planting Spinach Seeds
1.Fill the container with potting mix medium, leaving 3” – 6” of space at the top.
2.Moisten the medium with nutrient water.
3. Fill the nutrient water reservoir if you’re using a self-watering container.
4. Sow seeds 1/2 inch deep, spacing them 2-3 inches apart.
5. Cover the seeds lightly with medium and gently water again.
The first time you water will be from the top, after that, use the self-watering “trough” located near the bottom of the container.
Caring for Spinach Plants
If you’re using a self-watering container, check water levels every couple of days. Water your spinach plants deeply when the top inch of soil feels dry. Avoid overwatering, as this can lead to root rot.
Monitor your spinach plants closely and adjust the light settings if needed. As the plants grow, raise the lights to maintain the optimal distance.
Managing Pests and Diseases
Though less susceptible indoors, spinach can be affected by pests and diseases. Common threats include aphids, fungus gnats and fungal diseases.
Organic methods like insecticidal soap and neem oil can be effective in controlling pests. Small sticky traps are effective at controlling flying pests like fungus gnats. Maintain good sanitation and avoid overwatering to prevent fungal diseases. Read more about organic pest control on Roots & Refuge.
Harvesting Spinach
Spinach is ready for harvest when the leaves are 4-6 inches long and tender. Harvest individual leaves or cut the entire plant at the base with scissors.
Regular harvesting encourages new growth, ensuring a continuous supply of fresh spinach. Store harvested spinach in the refrigerator for up to 5 days.
Growing spinach indoors with Happy Leaf LED lights is a rewarding and accessible way to enjoy fresh, delicious spinach all year round. This guide provides a solid foundation for successful cultivation, empowering you to nurture thriving spinach plants in the comfort of your own home.
Are you really giving your plants the best possible environment with a south facing window? We sometimes hear gardeners talk about the success they have starting plants in a south facing window, or how they can keep some plants happy in the winter just using a south facing window. What comes to mind for us, as a grow light manufacturer, is that we hope you will consider that even the loveliest south facing window is not giving your plants the best possible environment for growth and survival. Even if the window is not covered in a coating that blocks sunlight, winter days are still much too short to provide the ideal amount of daily light most plants need.
The Limitations of South Facing Windows
If you happen to have an ideal-sized window that faces true south, then you’re pretty lucky because it is possible to have some level of success with keeping plants alive or starting seeds. While some folks are happy with the results they get from a south facing window, anyone who has decided to take a leap and try a really great grow light, will tell you there is definitely a real bonus for your plants if you pick the right grow light.
Understanding Daily Light Integral (DLI)
We all know plants need sufficient amounts of light to grow robustly. The word “sufficient” is very important here. I am going to mention one technical term and I promise this will be the only one. Plants need their daily dose of light and the technical term for this is Daily Light Integral or DLI. It is the average intensity of the light multiplied by the total number of hours of light that the plants are getting. For example, lettuce, herbs, and microgreens need a DLI of 3 to 5 per day whereas tomatoes and peppers may need a DLI of 10 to 15 per day.
By the way, the units for DLI are moles of photons per square meter per day for those of you who are curious. That is all we will say about DLI but I think you get the point that what really counts is the amount of light our plants get each day.
Challenges of Winter Sunlight
The challenge for those of us living in the northern half of the US is that the days get pretty short in the winter (i.e. 6 to 8 hours of reasonable sunshine) and that many of the days in the winter are cloudy or overcast. So we may only be getting on average 4 to 6 hours of sunlight per day.
On top of that, the windows we all have in our homes have special coatings on them to improve their ability to insulate from the cold and to reduce the amount of light entering our homes in the summer to reduce our air conditioning cost. These coatings are called low emissivity or Low E coatings. These coatings block about 75% of the light from the sun.
Add these factors together and it turns out that we are lucky if we can get enough light through our windows to keep our plants alive and maybe grow some microgreens. If we were hoping to grow plentiful amounts of greens, herbs, or possibly some cucumbers or tomatoes, we will most likely be disappointed.
How Do Grow Lights Fix The Problem
High quality grow lights that use very efficient LEDs will enable you to grow pretty much any plants you would like quickly and efficiently for just pennies a day. They use the proper ratio of red to blue to green light as well as the right intensity for growing everything from arugula to tomatoes. Turn on your light that can be in your basement, closet, or kitchen for 14 to 18 hours per day and you will be amazed at your winter bounty.
And that brings us to flexibility. With Happy Leaf LEDs, you won’t have to locate ALL OF YOUR PLANTS IN ONE WINDOW…. or, only in south facing windows…. or, in any windows at all. You can grow herbs on a shelf in your kitchen, lettuce in your living room and tomatoes in your basement! No windows (north, south, east or west) required.
