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342-An Introduction to Growing Microgreens  

| Grow, Podcast

Growing microgreens is easier than you think. Nutrient-dense microgreens can be raised at home for your family’s enjoyment, and it’s easy to scale up into a microgreens business, according to my guest this week, Jonah Krochmalnek, the owner and founder of Microgreens Consulting.

Jonah is the founder of Toronto-based Living Earth Farm, one of the largest microgreen farms in Canada, specializing in organic microgreens and baby greens. After nearly 10 years of running the business and doubling production nearly every year, Jonah began doing more and more education work, consulting with farms and helping others learn how to start a successful microgreens business. He decided to sell his business this spring so he could focus full-time on education. Through his online course, he has helped 4,000 people start microgreens businesses. He also started the “Microgreens Mastery” podcast and speaks to microgreens farmers worldwide.

 

Jonah Krochmalnek

Jonah Krochmalnek is the founder of Microgreens Consulting and earlier this year sold Toronto-based Living Earth Farm, which he also founded. (Photo Courtesy of Jonah Krochmalnek)

 

Jonah didn’t have a farming background in his family, but his father had a garden. “I started getting excited about seeing plants grow and trying my first real cherry tomato,” he says. Having a real, fresh tomato, instead of what’s available at the grocery store, is a profound experience, he notes.

That experience planted a seed in his mind that gardening is a great hobby, and he started his own garden at 13 or 14 years old. His friends in his Toronto high school would ask him why he was gardening and called it an older person’s hobby. He brushed it off.

“I knew I found something I loved because I didn’t care what they said,” Jonah recalls. “I would go home after school and plant more vegetables in the backyard, and harvest, and just found so much pure joy in that experience.” 

When he went to university, he studied finance and saw a practical career path before him. At his summer job as a regulator for pension funds, he would bring a bowl of his home-grown cherry tomatoes into the office and offer them to everyone who worked on his floor. 

“People’s faces would just absolutely light up with joy, trying this for the first time, same way that I had when I first had my first cherry tomato,” he says. “And just seeing that and allowing others to experience that was probably one of the most satisfying moments I’ve ever had. I think that was like the reinforcement that I needed to go down another path.”

Still he didn’t expect he could make a career out of gardening or farming. Once out of school, he took a job in commercial real estate appraisal. He said he felt like he didn’t fit in, similar to how he felt at university. 

Jonah started volunteering at a greenhouse that was growing microgreens, and that really turned up his interest in farming. However, he still worried it would not be viable. “To be honest, farming in general is really hard to make a living at,” he notes. 

At first, he wanted to be an outdoor farmer but realized how difficult it was. Over a summer at a farmers market he made only $5,000. But with microgreens, he could grow them not only in a greenhouse on a farm but also indoors and year-round. Applying his business acumen and crunching the numbers, he realized that he could make a living raising microgreens.

If you want a comprehensive guide on how to start growing microgreens, you can download Jonah’s free Microgreens Mastery ebook.

Why Microgreens Are Profitable

Microgreens take up very little space, and they take between seven and 10 days to get from seed to harvest, which Jonah says is otherwise unheard of in gardening. 

In the winter months, the produce typically sold in the Toronto area is shipped from California, Arizona or Florida and spends six to eight days in transit before hitting the shelves. “Unless you’re eating it the same day, it’s just not fresh anymore,” he says.

Jonah started growing microgreens in 2013 in a 150-square-foot spare bedroom. When he ran out of room he moved into the basement, and he earned $40,000 over the course of six months selling what he grew in that basement.  Then in 2015 his hobby grew into a legitimate business and he moved into a commercial facility.

Now Jonah helps others to start microgreens businesses.

“Growing food and doing that for a living is, I think, very transformative for yourself and then the people around you,” Jonah says.

Microgreens are not only easy to grow, they are also the most profitable legal cash crop, according to Jonah. One metal baker’s rack with five levels can accommodate four trays per level, and each tray will sell for about $25 direct to consumers. That’s $500 per week, or $2,000 per month, per rack. And a rack only takes up six square feet of floor space.

“If you just keep expanding that, it becomes, pretty quickly, a business that can replace your current income,” Jonah says.

 

Broccoli micro

Broccoli microgreens. Microgreens can be turned for a profit with much less upfront investment and time commitment, compared to crops to maturity.
(Photo Courtesy of Jonah Krochmalnek)

 

Why Microgreens Are Nutrient Dense

Microgreens are young plants that are between sprouts and baby greens. They are harvested at anywhere from seven to 21 days, while baby greens are harvested at between 30 and 40 days.

Microgreens have numerous health benefits. “They actually are one of the most nutrient-dense foods on the planet on a calorie basis,” Jonah says. 

He says the analogy he uses is how much energy a toddler has. A toddler has boundless energy compared to a mature adult.

In microgreens, there are a lot of growth factors at play, he says. Many we don’t understand yet but in the next decade or two, he expects, plant science and soil science will answer many of the questions that remain.

“There’s a combination of just that energy factor where the plant needs to grow to survive,” he says. “So it’s putting out a lot of energy to grow, so it’s going to store up more nutrients.”

Plus, antioxidants and phytonutrients are often a defense mechanism of plants, he adds. “Young plants are very vulnerable, so they need something to protect themselves.”

For example, broccoli microgreens, the most studied microgreens, have a higher concentration of sulforaphane, a phytochemical used as a defense mechanism, than mature broccoli. (When consumed, sulforaphane is said to reduce inflammation and cancer risk.)

Across horticulture, this is known as “juvenile vigor.” For example, when propagating plants from cuttings, you will have much more success taking tip cuttings — new growth — than cuttings from old stems.

 

Microgreens

Microgreens contain a much greater nutrient density than mature vegetables.
(Photo Courtesy of Jonah Krochmalnek)

 

Grow Microgreens in a Small Space

The second best reason to grow microgreens is how easy it is and how little space is required, according to Jonah. For growers like Jonah in the North, where there is a short growing season, microgreens offer an opportunity to grow indoors and satisfy the gardening itch in winter.

 “So you can grow a tray of microgreens, which is about 10 inches by 20 inches. Plant it, have it ready in seven to 10 days, generally speaking, depending on the variety, sometimes more. And then have a crop to eat that not only tastes really good, is really nutritious, but super fun to grow in the process because each day you see how much it grows. They grow so fast,” Jonah says.

An indoor growing space of 70 to 75 degrees with good humidity is great for microgreens.

The Diversity of Microgreens

Jonah says many people think microgreens are limited to just a few crops —Broccoli, kale, cabbage — but there are hundreds of crops to choose from. And not every crop is mild-flavored like broccoli microgreens. Arugula microgreens are spicy and peppery, and mustards are spicy as well. Basil and cilantro and two more flavorful options, and Jonah says cilantro microgreens don’t have the soapy flavor that is often associated with mature cilantro.

Garlic chives, onions, amaranth, beets, carrots and lemon balm are all viable as microgreens.

“Pretty much any plant that you can eat the edible top of you can grow as a microgreen,” Jonah says. “So for example, you can’t grow tomato as a microgreen because you can’t eat a tomato plant, but you can eat a carrot top so you can grow carrots as a microgreen.”

 

Growing microgreens

There are scores of crops that can be raised as microgreens. (Photo Courtesy of Jonah Krochmalnek)

 

Eating Microgreens

Jonah says microgreens are pretty much very small baby salad greens and so they fit into any diet— vegan, vegetarian, paleo, keto, etc. In any dish that calls for baby salad greens, he replaces them with microgreens and enjoys better flavor, greater nutrient density and less bitterness.

His favorite way to enjoy microgreens is in smoothies. It’s a great way for anyone who isn’t inclined to eat salad greens to incorporate them into their diet. When you add broccoli, kale or cabbage microgreens to a smoothie, you barely taste it, Jonah notes. 

“It’ll turn the smoothie green for sure, but because they have such a mild flavor, you’ll get all that nutrition without that ‘green’ flavor,” he says. He adds that he wouldn’t put something like basil in a smoothie and sticks to the more mild-flavored microgreens. 

Many of his restaurant clients use microgreens as garnish. They can also be added to soups or stuffed in pita.

 

microgreens on bread.

Any meal that calls for baby salad greens can use microgreens. (Photo Courtesy of Jonah Krochmalnek)

 

Microgreens and Nutrition

When it comes to cooking vegetables, whether they be microgreens or mature, cooking can reduce the nutrient content. Jonah says minerals will be unchanged and vitamins will break down to a certain degree. But cooking also makes vegetables easier to digest, which makes certain vitamins more bioavailable when compared to raw vegetables.

For example, Jonah explains, vitamin C is heat sensitive and breaks down when cooked, but vitamin A (beta-carotene) is more available in cooked kale than raw kale. 

Microgreens don’t contain an exceptional amount of minerals as compared to mature vegetables because plants only contain the minerals available to them in soil, Jonah says. But plants create vitamins and antioxidants, and those are much more dense in microgreens than mature vegetables, he explains. This means getting much more nutritional value while eating much less. 

What You Need to Start Growing Microgreens

There are roughly 10 items you need to get started growing microgreens, according to Jonah.

Grow lights – You could potentially grow microgreens in a south-facing windowsill, but in the winter months most places on the planet don’t get a lot of sun. Grow lights will be much more reliable, and the greens will grow more vigorously and be of higher quality because light helps them absorb nutrients from the soil. 

Shelving unit – A shelving unit isn’t a must-have if you are only growing one tray of microgreens at time, but if you intend to have a few going, shelves will allow you to grow a lot without taking up too much floor space.

Easy Varieties – When getting started, it’s wise to plant fool-proof crops before moving on to more demanding vegetables. Jonah says the easist to grow are peas, broccoli, kale and radish.

Soil – For a growing medium, you need potting soil or a soiless potting mix.

Fertilizer – For vigorous, crunchier and more nutrient-dense microgreens, fertilizer will be needed.

Trays with holes – Ensuring proper drainage is vital so microgreen roots won’t drown in overwatered trays. Microgreens trays, or germination trays, are about 11” by 21” and half the height of nursery trays. 

Trays without holes – Microgreens are grown inside the trays with holes, but those trays sit in a tray without holes so you can water from the bottom. Trays should be filled to the top with soil so the microgreens get good airflow and the greens can be cut and harvested easily. Because the trays are half the height of nursery trays, they require less soil to fill to the top.

Light timer – A timer to control when the lights turn on and off will maintain the appropriate number of hours of light the microgreens are under daily. 

Scale – An inexpensive scale will allow you to track how much seed you are planting per tray, which lets you know how much of a yield to expect per tray.

 

 Jonah Krochmalnek growing microgreens

With shelves, lights, trays, soil and a few more things, you’ll be on your way to growing microgreens, like Jonah. (Photo Courtesy of Jonah Krochmalnek)

 

Lighting Microgreens

When Jonah began growing microgreens in 2012 and 2013, the most common grow lights were fluorescents. LEDs were new to the scene and very few greenhouses were using them. In 2014, he bought LED grow lights directly from the manufacturer overseas because there was almost nothing available locally back then, he says.

Many grow lights today are white, which means they include the full spectrum of light: blue, green, yellow and red.

Plants can absorb all wavelengths of light but some wavelengths they absorb better than others, so you can use less power while getting more growth from your plants, Jonah explains. The two specific wavelengths that are best for plants are a 460 nanometer blue light and 660 nanometer red light.

“The lights I recommended give the full spectrum, but they focus on those two wavelengths because you’re going to get more output for each watt of electricity that you give the plants,” Jonah says.

You can use regular white LED lights if the appearance of the grow lights is a consideration for you.

“It’s crazy how much the cost has gone down on these lights,” Jonah says.

He has all of his recommendations for grow lights in his Microgreens Mastery guide. His primary recommendation is a Barrina four-foot T8 full spectrum light, with three lights per level of the shelving unit. 

 

Soil and Fertilizer for Microgreens

The way to get soil with the most nutrients possible is to use the best soil and fertilizer, according to Jonah. He uses a potting soil like Pro-Mix. A non-organic Pro-Mix option is for microgreen is HP. Because Living Earth Farm is certified organic, he uses the Pro-Mix organic option, MP. Both are peat-based and treated with mycorrhizae. He avoids potting mixes that contain coir because coir contains a considerable amount of salt. 

Peat moss is a great growing medium without the drawbacks of coir, but peat moss is not sustainable, so I am moving away from using it when practicable, and Jonah shares my concerns.  

Jonah calls soil with fertilizer added “super soil.” When he tested microgreens grown without fertilizer and grown with, the difference in nutrient levels was clear. A nutrient analysis showed that protein levels were 41% higher and iron levels were 200% higher. “It’s just a testament to how important having a good growing recipe is,” he says.

Microgreens grown in fertilizer not only have a higher nutrient content but also bigger leaves and are thicker and crunchier. Jonah says the taste is also better and the shelf life is longer once cut.

Jonah says he did unbelievably extensive testing of fertilizers. He found the best is Gaia Green 4-4-4. It’s organic and powdered, and it contains alfalfa meal, rock dust, bat guano, insect frass, blood meal, bone meal and more.

“I was lucky early on to speak to the owner of Gaia Green — who I have no affiliation with — but he just explained how important the diversity of the nutrients in your soil are for the growth of the plant. And I saw it because there’s no other fertilizer that I’ve experienced that’s comparable to the Gaia Green product because it has like 15 or 16 ingredients. And it’s great that it’s powdered because it makes it more bioavailable for the plants. The bacteria and fungi can break it down a lot faster, which is really important for microgreens because it’s such a short crop cycle.”

A small amount of dolomitic lime can also be added to the soil to raise the calcium and magnesium levels, but Jonah says it is not necessary when starting with a good potting mix. 

The used soil can be added to your garden. The peat moss and fertilizer will improve your garden soil. Soil reused indoors for microgreens may have ungerminated seeds that will sprout when the soil is reused, and mold and disease issues will recur if soil containing pathogens is used again.

Watering Microgreens

Because microgreens are seeded so densely, watering from the top can cause mold to grow on the soil surface. Bottom watering, or subirrigation, is the way to go. The capillary action of soil will absorb water added to the tray

During germination, he waters just the top inch of the soil. Bottom watering begins after germination. 

After germination, Jonah waters soil to near the point of saturation. He waits an hour and lists the tray with holes out of the solid tray. If the solid tray has pooling water, the soil is overwatered. If all the water is absorbed, more water can be added.

Jonah picks up trays and gets a sense of the weight of a saturated tray. If a tray feels light, he knows it’s time to water.

 

When bottom watering, the capillary action of soil will absorb the water added to the tray until the soil becomes saturated.

I prefer bottom watering because there is no risk of water damaging tender seedlings.

 

Sowing Microgreens

Rather than trying to count out the right number of seeds to fill a microgreens tray at the appropriate density, Jonah advises weighing the seeds.

Broccoli – 10 grams

Kale – 9 grams

Radish – 22 grams

Pea shoots – 350 grams

Broccoli, kale and radish seeds can be dry when added to the soil. Pea seeds soak up a lot of water so it’s easier to let them set in water for eight to 12 hours before sowing.

Jonah likes to top seeds with fine vermiculite, but he says that is hard to find and not necessary. The vermiculite will help retain moisture and insulate the seeds. Jonah also finds that vermiculite reduces mold and damping-off (Pythium) problems. He doesn’t recommend top dressing seeds with soil because the soil tends to crust, which vermiculite won’t. 

Then mist the soil surface once a day and put an empty tray on top to keep the soil moist and ensure the seeds have soil contact. After two to three days like this indoors, the seeds should germinate. The empty tray on top should come off at this point so the sprouted seeds can get light.

Harvesting Microgreens

From day four to nine, check on the microgreens daily and add water as necessary. Then on day 10, take the crops out of the growing area to a kitchen or another prep area. Grab sections of microgreens and cut them off with a sharp knife, adding them to a bag or bin. You can cut a whole tray in just two or three minutes if not faster, Jonah says.

Microgreens Sanitation

After harvesting, clean the trays so any mold spores or other pathogens are removed before moving on to the next crop of microgreens.

“Each time you grow, if you don’t clean your trays, increases the risk of potentially getting Pythium in the soil or in the tray,” Jonah says,

Clean all the soil and root matter residue off the tray first, then disinfect. The order of these steps is important because pathogens can hide in stuck-on soil. His disinfectant of choice is ZeroTol, an organic product. It is made with hydrogen peroxide and vinegar. In Canada, it’s regulated and requires a pesticide license to buy, but in the United States, anyone can buy it.

Another option is 5% acetic acid vinegar. He doesn’t recommend bleach because it is toxic to breathe and toxic to plants.

 

Microgreens on brioche

Once you start growing microgreens, you’ll find countless ways to add them to your diet. (Photo Courtesy of Jonah Krochmalnek)

 

If you haven’t listened to my conversation with Jonah Krochmalnek about growing microgreens, you can do so now by scrolling to the top of the page and clicking the Play icon in the green bar under the page title. 

Have you tried growing microgreens? Let us know in the comments below.

Links & Resources

Some product links in this guide are affiliate links. See full disclosure below. 

Episode 238: Peat Moss: Examining the Challenges of Its Ongoing Use in the Face of Climate Change

Episode 256: The Challenge (and Solution) for Using Coconut Coir as a Seed Starting and Growing Medium

Episode 270: Plant Science for Gardeners, with Robert Pavlis, Part I

Episode 283: A Soil Chemistry Primer: How Protons and Electrons Influence Soil Moisture and Fertility

The Best of the Must-Haves™ Resource Guide

joegardener Online Gardening Academy™: Popular courses on gardening fundamentals; managing pests, diseases & weeds; seed starting and more.

joegardener Online Gardening Academy Organic Vegetable Gardening: My new premium online course. The course is designed to be a comprehensive guide to starting, growing, nurturing and harvesting your favorite vegetables, no matter what you love to eat, no matter where you live, no matter your level of gardening experience.

joegardener Online Gardening Academy Master Seed Starting: Everything you need to know to start your own plants from seed — indoors and out. 

joegardener Online Gardening Academy Beginning Gardener Fundamentals: Essential principles to know to create a thriving garden.

joegardener Online Gardening Academy Growing Epic Tomatoes: Learn how to grow epic tomatoes with Joe Lamp’l and Craig LeHoullier. 

joegardener Online Gardening Academy Master Pests, Diseases & Weeds: Learn the proactive steps to take to manage pests, diseases and weeds for a more successful garden with a lot less frustration. Just $47 for lifetime access!

joegardener Online Gardening Academy Perfect Soil Recipe Master Class: Learn how to create the perfect soil environment for thriving plants.

Earthbound Expeditions: Discover South Africa with Joe Lamp’l

joegardener Newsletter

joegardener Facebook

joegardener Facebook Group

joegardener Instagram

joegardener Pinterest

joegardener Twitter

joegardenerTV YouTube

Growing a Greener World®  

GGWTV YouTube

Microgreen Consulting on YouTube

Microgreen Consulting on Instagram: @microgreensconsulting

MicrogreensConsulting.com

Microgreens Mastery: Your Expert Growing Guide

Free Microgreens Webinar Training

“Microgreens Mastery” podcast on Spotify

“Microgreens Mastery” podcast on Apple Podcast

 Living Earth Farm

Barrina four-foot T8 full spectrum light

Microgreens trays with holes

Microgreens trays without holes 

ZeroTol

Light timer 

Scale 

Dolomitic lime 

Pro-Mix HP

Pro-Mix MP

Gaia Green 4-4-4.

Greenhouse Megastore – Our podcast episode sponsor and Brand Partner of joegardener.com – Enter code JG10 for 10% off your order

Disclosure: Some product links in this guide are affiliate links, which means we get a commission if you purchase. However, none of the prices of these resources have been increased to compensate us, and compensation is not an influencing factor on their inclusion here. The selection of all items featured in this post and podcast was based solely on merit and in no way influenced by any affiliate or financial incentive, or contractual relationship. At the time of this writing, Joe Lamp’l has professional relationships with the following companies who may have products included in this post and podcast: Corona Tools, Milorganite, Soil3, Greenhouse Megastore, Territorial Seed Company, Earth’s Ally, Proven Winners ColorChoice and Dramm. These companies are either Brand Partners of joegardener.com and/or advertise on our website. However, we receive no additional compensation from the sales or promotion of their product through this guide. The inclusion of any products mentioned within this post is entirely independent and exclusive of any relationship.

About Joe Lamp'l

Joe Lamp’l is the creator and “joe” behind joe gardener®. His lifetime passion and devotion to all things horticulture has led him to a long-time career as one of the country’s most recognized and trusted personalities in organic gardening and sustainability. That is most evident in his role as host and creator of Emmy Award-winning Growing a Greener World®, a national green-living lifestyle series on PBS currently broadcasting in its tenth season. When he’s not working in his large, raised bed vegetable garden, he’s likely planting or digging something up, or spending time with his family on their organic farm just north of Atlanta, GA.

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