Microgreens 101

Growing microgreens is easier than you might think! They sound fancy and are used by top chefs around the country, but really it's just growing a bunch of tiny plants all at once. There are definitely pitfalls to avoid and a process to follow to get it right with the least amount of grower's heartache. Whether you are an experienced gardener or a first-time grower, you can absolutely grow successful microgreens at home, either for yourself and your family or as a startup business.

What do you need to grow microgreens at home?

To grow microgreens at home, you need some basic materials, including:

• Microgreens seeds like these
• Shallow trays like these (although other DIY options will work too)
• Growing medium like potting soil, coco coir, or hemp mats
• A light source

But you're not here to just get by growing microgreens - you want to rock it! You can take things up a notch to maximize your yield and production by following our step-by-step guide below. We break it down just enough so that any beginner can start growing microgreens at home and feel like they're a pro in no time.

Step by Step Guide to Growing Microgreens at Home

1. Select your seed type 
2. Prepare your growing trays
3. Plant your seeds with the correct seed density
4. Keep your trays evenly moist
5. Watch your beautiful microgreens grow
6. Harvest and store 
7. Eat with delight

Which Microgreen Variety is Right For You?

The microgreen varieties that you choose to grow the most of are going to vary based on your taste and goals, but the tried and true, most popular seeds to start with are broccoli, pea, radish, sunflower, purple kohlrabi and clover. 

• Broccoli is easy to grow as a microgreen and popular for its mild flavor and documented nutritional value (1).
• Pea shoots are slightly sweet and highly versatile in the kitchen, plus kids love them. (One of our Bootstrap Farmer kiddos has been known to eat a whole 1020 tray worth in a single day)
• Radish microgreens are the fastest growing and have a delightful spice that is tempered when used in warm soups and noodle dishes.
• Sunflowers are the sweetest of all the popular microgreens, making them great to have microgreens at home for use in smoothies and lunch boxes. Also, they are considered a very nutritious crop containing proteins and amino acids (2).
• Purple kohlrabi is a great variety  to try as it is easy to grow, quick to germinate and carries a mild flavor. It is an especially great addition to salads, sandwiches and cold noodle dishes.
• Clover is a favorite for those looking for a nutty flavor and exceptional high nutritional value. It is a quick sprouter and a versatile crop that many find desirable as a microgreen (3).

Get your Microgreens Seeds

There are many great places to get microgreen seeds. When you are shopping for microgreen seeds, buying from a reputable supplier is important. Because microgreens are more susceptible to carrying food-borne illnesses than their mature counterparts, starting with clean seeds is doubly important. Many of the larger seed suppliers carry lines of microgreen seeds sold in larger quantities, either by the ounce or the pound. It is always less expensive to buy seeds in bulk rather than in small packets. 

Check out: Top 10 Microgreens to Grow

Online seed suppliers are usually the best way to order bulk microgreens seeds. However, given the rise in the number of people choosing to grow microgreens indoors at home, many hardware or farm supply stores are starting to carry lines of microgreen seeds. Whichever way you decide to purchase your seeds, pay attention to the "Packed for Year ____." This lets you know when the seeds should be used by as most types will decline in germination rate after a year of storage. 

Always use seeds intended for human consumption when growing microgreens. Seeds sold as animal feed do not undergo the same rigorous testing.

Prep your Microgreens Trays and Growing Space

Prepare your microgreen growing space with a thorough cleaning. Wash all of the trays and equipment with hot soapy water and allow to air-dry. Bootstrap farmer trays are sturdy enough to be washed in the top rack of the dishwasher. Just be sure to turn off the heated dry cycle.

Whether growing indoors or out, your microgreens will need at least six to eight hours of direct light available for proper growth. This light can come from the Sun or specialized growing lights. Even something as simple as an LED shop light can be used to grow microgreens. Microgreens will grow faster the more hours of light they have available. If you are using artificial light, you can set the cycle for up to 18 hours of light. Plants need at least a few hours of darkness to grow properly.

Want to learn more about lighting? Check out Lights for Growing Microgreens?

Growing microgreens indoors 

To grow microgreens indoors, you will need a light source. This can be as simple as a sunny window sill or a specially installed grow light. Growing microgreens with under-counter LED lights can be a space-saving way to have microgreens available at your fingertips in the kitchen. 

Growing microgreens outdoors

You will be growing your microgreens outdoors. A small greenhouse or high tunnel is ideal for protecting them from hungry birds. Depending on the overnight temperatures in your area, you may want to bring your microgreen trays in at night. Although, some of the cold-loving crops like purple bok choy and red cabbage will get a beautiful color boost from being exposed to lower temperatures. If freezes are expected in your area, always bring your tender plants inside.

Use Our Cheat Sheet and Sow Your Microgreens Seeds

Seed density is important in growing microgreens. Too little, and you will have spotty trays that are difficult to harvest and end up wasting growing space. Too much and the greens will crowd each other leading to more small plants, and you may run into mold issues. While every growing space will be a little different depending on temperature and airflow, using a guide to get you started will help you be successful at the start.

Bootstrap Farmer Ultimate Microgreen Cheatsheet is a printable chart designed to give you the correct seed density for over 40 types of seeds. The cheat sheet provides recommended seed density in grams as well as expected time to germination and until they are ready to harvest. Once you have selected the type you want to grow and know the correct seed density, you can begin your sowing.

Sprinkle the seeds over your growing media by hand. Try to sow the seeds evenly across the entire surface to avoid clumping and bare spots. 

Seeds can also be distributed based on the number of seeds per sq. inch for anyone without access to a scale. For smaller varieties, this is 10-12 seeds per square inch. For larger seeds, it will be around 6-8 seeds per square inch. 

From Sowing to First Germination - What to Do to Maximize Germination Rate

You want your potting soil, growing media or growing mat to stay evenly moist but not soaking wet throughout the germination process. Overly wet potting soil is too much water for microgreens and can rot seeds before they have the chance to sprout. Seeds that dry out after being wet are far less likely to sprout. 

It is best to germinate microgreens indoors. This protects them from pests as well as from temperature fluctuations overnight. Even if you will be moving your growing microgreens outdoors, it is best to keep them at an even temperature until they are around half an inch tall. If the space you have to grow your microgreens at home is unheated, you can use a heated growing mat to provide the best temperature for germination.  

Not sure how to use a heat mat? Check out How to Use Heat Mats for Starting Seeds for a list of the best practices.

Stacking your trays on top of each other or covering them with a humidity dome during the germination phase will help maintain moisture levels without you needing to water them a few times per day. 

You can also use an empty tray on top of your growing seeds to help maintain seed-to-soil contact and retain moisture. Putting a small amount of weight in the empty tray will help with this. 

Want to learn about ways to avoid spotty germination in your trays? Check out this article.

When and How Much to Water Your Microgreens

When starting your microgreens, you want your growing media to be evenly moist but not completely saturated. Using a spray bottle with a heavy mist setting is best to water your microgreen seeds until germination is achieved. Once all of your microgreens have sprouted, you will want to water from the bottom to avoid wetting the leaves.

Check out:  How to Water Microgreens | Which Method is Best

Throughout the germination phase, you want to keep the seeds and growing media evenly moist but avoid adding so much water that puddles form. If you have stacked your microgreens or used a humidity dome with the vents closed, you will likely not need to water your microgreens more than once during the germination phase. If it is exceptionally dry or warm where you are growing, you may need to water more frequently. 

Check out:  How to Use a Humidity Dome for Seed Starting

Soaking long cycle microgreen seeds

For larger microgreen seeds like peas, sunflowers, or cilantro, you will want to soak them before placing them on the trays. 4 to 6 hours is enough soaking time for most seeds. This helps loosen the seed coat and begin the germination process. After your seeds have soaked, rinse them until the water runs clear and leave them in the colander to sprout. Within 12 to 24 hours, you will see the beginning of the root poking through the seed. At this point, you will sow them on your prepared tray and stack or cover them with a humidity dome.

Check out: Microgreens & Soaking Seeds- When & Why

Tips for Harvesting Microgreens (How to Tell When They're Ready)

To harvest microgreens, you will need clean scissors or a small, sharp kitchen knife. Cut the microgreen stems just above the soil line. Most people choose to harvest as much of the stem as possible to get the most significant nutritional value and fiber content for personal use. When harvesting microgreens for sale, many chefs prefer a shorter stem to leaf ratio. 

Learn about how to prepare your microgreens in 10 of the Tastiest Ways to Enjoy Microgreens.

Quick growing microgreens

Most of the easy-to-grow microgreens will germinate in 2 to 3 days and be ready to begin harvesting around the 10th day from planting. For easy harvesting, the stems should be at least 1 and 1/2 to 2 inches tall. This includes radishes, broccoli, mustards, kale, collard greens, and other quick-growing brassicas.

Long cycle microgreen crops

Peas and sunflowers are the most popular long cycle microgreen crops. Both microgreen varieties require soaking and sprouting before planting. Most long-cycle crops will complete their germination in 3 to 4 days. They are ready to harvest when they reach 3 to 4 inches in height. Sunflowers are best harvested before the first set of true leaves forms. These secondary leaves are spiky and will render the sunflower microgreens bitter.

Many other long-cycle microgreen crops like amaranth are grown until they have at least one to two sets of true leaves. Pea shoots should be harvested about an inch above the soil line or just above the bottom set of leaves. If left this way, they will often produce a second edible crop.

Growing herbs as microgreens

Herbs take the longest to grow as microgreens. Many microgreen varieties need to stay in the tray for 20 or more days until they are ready to harvest. The stems of herb microgreens also tend to be shorter. Microgreens can be harvested as soon as the stem reaches about an inch in length. For the best flavor, keep your growing herb microgreens under lights until at least one set of true leaves has appeared. 

Cleaning your microgreen equipment

After every harvest:

1. Clean your microgreen trays.
2. Once you are finished cutting the microgreens, move the tray outside as soon as possible to avoid attracting pests or providing an environment where mold can flourish. Not sure how to recognize mold? Check out Microgreens- How to Combat and Prevent Mold.
3. Dispose of the remaining roots and grow media from the microgreen tray according to your preferred method. If you are looking for ideas on what to do with spent trays, check out our article on Reusing Spent Trays of Cut Microgreens. 

Our shallow microgreen trays are sturdy enough to handle a hard spray with the hose to knock off any roots or growing media stuck to the sides of the trays. Wash the trays with hot soapy water and allow to air dry. You can sterilize your trays for extra protection by dipping them in a mild bleach solution or giving them a quick misting with a 3% hydrogen peroxide solution. (Always use appropriate safety gear when dealing with chemicals.) Allow the trays to dry completely before stacking them away for storage. Check out How to Wash and Care for Seedling Trays for more information on proper cleaning and storage of microgreen trays.

How Long Will Fresh Microgreens Last After Harvest?

Freshly harvested microgreens will last 7-14 days in the fridge. If you are harvesting your microgreens all at once to store, save the washing (if you choose to) until right before you eat them. Packaging freshly harvested microgreens, while they are wet or even just damp, will significantly reduce their shelf life. Placing a folded paper towel into the bottom of your storage container will help absorb excess moisture. 

Often when you buy microgreens from a store, they are several days past harvest date before you get them home. This has led many people to the belief that microgreens have a short shelf life. When you are growing microgreens at home, though, nothing could be further from the truth. Because you are putting them into your fridge at peak freshness, they will frequently last longer than almost any kind of store-bought greens. 

Basil microgreens are the one exception to this rule, as basil microgreens are better stored at room temperature. They will last longer using this method as the delicate greens tend to wilt in the refrigerator. 

Can I Eat Microgreens if They Get Too Big?

Yes, you can eat microgreens if they get bigger than expected before you have time to harvest. Most microgreens will become what is often referred to as baby greens once they grow past the first true leaf stage. Only a few microgreens, like sunflowers, undergo a dramatic flavor change and are best harvested right on time. Sunflowers will tend to get a sour, undesirable flavor once they reach the true leaf stage.

You may also choose to harvest a part of a tray at a time as needed. You can then leave the remainder of the plants on the tray growing until you are ready to harvest them for your next meal. This method works incredibly well if you want to have micro herbs available in the kitchen to finish off any dish with a great pop of flavor.

Remember that having partially harvested trays in your kitchen or growing space may attract pests like fungus gnats. Infestation is especially possible if your growing area does not have adequate airflow. The little yellow sticky traps sold by our affiliate over at Arbico are an excellent way to control this issue.

Where to learn more about growing microgreens?

If you are interested in growing microgreens as a potential home-based business, you can read more on our Ultimate Microgreen Growing Resource Guide. For more specific questions like, "what is the best growing media for microgreens?" check out the rest of our microgreen blog articles here. 

Resources

1. BROCCOLI MICROGREENS: A MINERAL-RICH CROP THAT CAN DIVERSIFY FOOD SYSTEMS 

"This study examined the mineral concentration of broccoli microgreens produced using compost-based and hydroponic growing methods that are easily implemented in one's own home. The nutritional value of the resulting microgreens was quantitatively compared to published nutritional data for the mature vegetable."

2. A REVIEW OF PHYTOCHEMISTRY, METABOLITE CHANGES, AND MEDICINAL USES OF THE COMMON SUNFLOWER SEED AND SPROUTS (HELIANTHUS ANNUUS L.) 

"The sunflower (Helianthus annuus L.) seed and sprout is a ubiquitous crop with abundant nutrients and biological activities. This review summarizes the nutritional and medical importance…."

3.  Quantitation of Phytoestrogens in Legumes by HPLC
Adrian A. Franke, Laurie J. Custer, Carmencita M. Cerna, and Kavitha K. Narala
Journal of Agricultural and Food Chemistry 199442 (9), 1905-1913
DOI: 10.1021/jf00045a015