What is the difference between microgreens and sprouts?

Microgreens should not be confused with sprouts which are soaked and germinated in water, often in the dark, and for which the edible portion is constituted by the whole sprout, including the seedling, the radicles, and often what remains of the seeds. Sprouts take only a couple of days to produce their underdeveloped leaves and be ready for harvesting.

Microgreens grow in soil and sunlight, and the word “micro” here says it all, and microgreens are simply densely grown little seedlings of edible vegetables and herbs that, depending on the variety, are harvested anything from 7 to 21 days after germination. Microgreens are harvested when they have one or two fully developed cotyledon leaves with signs of the emergence of a rudimentary pair of first true leaves. The edible portion is constituted by single shoots which are harvested by cutting the young seedlings at the base right above the growing medium. These tiny versions only grow to a few centimetres high, and come in 50 to 60 different varieties and combinations.

Why are microgreens so healthy?

Microgreens are immensely popular for their nutritional properties, gaining the appellative of 'superfood'. All vegetables are a rich source of many nutrients that are critical for our health, including: dietary fibre, choline, vitamins A, C, K, E, and B1, B6,  and B3, as well as essential minerals like potassium, iron, zinc, copper, magnesium, and manganese.

Dietary guidelines advocate eating two and a half cups of vegetables a day, for a 2 000 calorie a day diet, and while microgreens are super nutrient-dense, they aren’t typically viewed as a substitute for regular vegetables due to the volume you would have to consume daily.

Compared to mature vegetables, microgreens are powerhouses of nutrition and flavour, with one study concluding that microgreens are up to 40 times more potent in phytochemicals than mature herbs and vegetables. Phytochemicals are known to strengthen the immune system, reduce inflammation, help prevent and repair DNA damage, and also slow down the growth of cancer cells. Analysis done on 25 different microgreens determined that on average, microgreens have four to six times more nutrients than their mature counterparts.

Studies have shown that red cabbage microgreens have 40 times more vitamin E and six times more vitamin C than mature red cabbage; and cilantro or dhanya microgreens have three times more beta-carotene than mature leaves of coriander. Among all the microgreens assessed, red cabbage had the highest concentration of vitamin C, cilantro had the highest concentration of carotenoids (a type of antioxidant found in brightly coloured foods), garnet amaranth had the highest concentration of phylloquinone (a type of vitamin K) and green daikon radish had the highest concentrations of tocopherols (a type of vitamin E).

How long do microgreens take before they can be harvested?

Although microgreens have a quick turnaround time, and most vegetable varieties are ready to harvest in approximately 2 weeks, it varies by variety, and environmental conditions will also have an effect on growth rate. Using herbs as microgreens is also a great option, but they tend to be slower growing and will mature in 16 to 25 days.

Members of the Brassica family like broccoli, Brussels sprouts, cabbage, cauliflower, collard greens, mustard kale, turnips and radish mature faster than carrots, beets or Swiss chard. Radish will be ready to harvest in only 9 days, peas and sunflowers in 15 days, and beetroot will take 12 to 18 days.

How much space do I need to grow microgreens?

These nutrient-dense tiny greens can be grown in small spaces, even on a windowsill or in your kitchen under good lighting.

What basic items do I need to grow microgreens at home?

Besides purchasing your seeds, growing microgreens at home does not require using any special tools or containers, and you should be able to find everything you need at home or in any home or gardening store. Perhaps you may prefer to start small with whatever you have on hand, but if you find your ‘green thumb’ and decide to grow microgreens continuously, for more efficient production, and to make growing more  convenient, consider buying some basics like growing trays, growing mats or medium, and small tools specifically designed to produce microgreens.

You will need:

• Seeds
  Drinking water
  Growing medium or growing mats
  Growing trays
  A small kitchen scale, or measuring cups  and spoons
  A spray bottle and a jug
  A colander
  A sharp knife or a pair of scissors
  A few cups for soaking seeds in water

Depending on whether you plan on growing your microgreens indoors or outdoors, you will also need a clean surface or shelf to place the growing trays on.

Where can I buy good quality microgreen seeds?

To avoid potentially dangerous poisoning, it is very important that you never use chemically treated seeds to grow microgreens. It is also important to use seeds of high quality, characterized by good germination rates,  and those which are specifically marketed to produce sprouts or microgreens, and have been produced and processed following high food safety standards and regulations to avoid any microbial contamination.

Microgreen seeds are becoming more freely available from garden centres, and online you will find a huge variety of unique blends to suit your particular tastes. These outlets will also stock everything else you may need to grow microgreens successfully at home.

The best seed companies will provide information on the quality of the seeds reporting a lot number, the average number of seeds per packet, germination rates and times, optimal germination and growing conditions, and an indication of the number of days required from germination to harvest. If the information on seed germination and harvesting times is not included, it may be worth doing your own germination tests and recording the results for future use.

What are the best trays to use for growing microgreens?

Trays and containers of various shapes and sizes may be used to plant microgreens, however, since microgreens do not require a lot of medium to grow on, flat rectangular trays are generally preferred over regular nursery pots. Some growers advocate using trays with drainage holes and drip trays underneath. This allows you to water the trays from the bottom without letting the water contact the greens. Others prefer trays without drainage holes, and water by carefully misting the soil as required. This method also works well as long as you do not overwater.

For a little extra expense you can purchase plastic trays with clear lids which are perfect for increasing humidity and creating a perfect environment for germinating seeds. These microgreen trays are made from recycled plastic and can be used for many years. They are also dishwasher safe, enabling you to easily and thoroughly wash the trays before reusing them.

Recycling plastic containers from food packaging or other items around the house is also an option. The main recommendation is to make sure you are using material that is suitable for food production, and that the trays are impeccably cleaned before using them.

What is the best growing medium for microgreens?

Because microgreens are harvested young, the availability of nutrients to the young seedlings is determined by the quality of the growing medium. The most popular media used are peat-based mixes, but because peat is no longer considered sustainable, palm peat would be a great substitute if mixed equally with perlite and a good quality germination or seedling mix, available from garden centres.

Coconut coir and mats constituted of natural cotton, kenaf or hemp, or synthetic fibres like rock-wool are also popular, but using these may require supplemental feeding. Basically you can use whatever good quality growing medium you have at home, or mix up your own, but ensure that all materials used are clean and have not been used before to grow other plants in. The soil must be clean and free from pests and diseases; therefore ordinary garden soil is not advisable.

Can I reuse my microgreen growing medium?

It is recommended that you use fresh growing medium each time you sow, and that you wash your trays well in hot, soapy water before reusing them. However, if you are growing indoors in a clean environment, you could use the growing medium a couple of times, but supplemental feeding may then be required. Once used up, any organic growing medium can be added to the compost bin, or simply be spread around garden plants as mulch.

Do I need to feed microgreens?

The availability of nutrients to the young seedlings is determined by the quality of the growing medium, and if you use a good quality medium you will not have to feed microgreens. If you feel the little seedlings need a boost, a single feed with a kelp based product will be sufficient. There are other suitable liquid fertilisers you can apply, so use what you have at home, but always feed with organic products only.

How much light do microgreens require?

Bright light is an important requirement if you want to grow healthy, tasty microgreens, and they need about four hours of direct sunlight daily to thrive. While the natural sunlight available behind a north facing window, balcony or a small porch is generally sufficient to grow microgreens, in the winter months when sunlight is weaker some microgreens may need even more sunshine, and pale and leggy-looking plants are a sure sign that the light is insufficient.

If you are growing microgreens you may need to supplement the natural sunlight with grow lights.
A fluorescent light will work well, and using the right combination of LEDs for microgreen grow lights will help improve the quality of your crops all year round. For microgreen production, it is suggested to use more blue than red colour, as blue will keep microgreens more dense.

What is the optimal temperature for growing microgreens?

Temperature will be variety specific, but 18 to 24 degrees Celsius can be viewed as the optimum range. A few cold night temperatures won’t affect growth too much, but ideally higher temperatures will encourage quicker growth.

How often must I water microgreens?

The amount of sunlight your seedlings receive, and also the growing medium used and its capacity to hold water, will determine how frequently you will need to irrigate. Try to keep the soil evenly moist but not soggy.

How to ensure successive harvests of microgreens?

You can only harvest or cut your microgreens once, so if you require continuous greens, you will need to do successive sowings. Basically, as soon as the first batch has germinated, it’s time to sow the next batch.

How to calculate and measure the optimal amount of microgreen seeds needed per tray?

After selecting the species of microgreens you would like to grow, you will need to calculate the amount of seeds you need for each variety, according to the size of your trays. Follow the instructions provided with your seed packets, and if your seed supplier does not provide this information, free Microgreen Seed Density Calculators are available online which can make things much easier for you, but you may have to convert from inches to centimetres. Click here to find a free density calculator from veg-geek.com

Generally, in 6cm² trays 10 to 12 small seeds can be sown per tray; and medium to large seeds are sown 6 to 8 seeds per tray. Radish is sown at 80g per tray; Sunflowers at 150g per tray; Peas at 200g per tray; Beetroot at 50g per tray, and Swiss Chard at 90g per tray.

Measure out the number of seeds you will need using a small home scale, and once you have the correct weight for the amount of seeds you will need for one tray, you can pour the seeds into measuring cups or spoons, taking notes on how many spoons or tablespoons a specific species needs to fill the size of your trays. Taking notes of your calculations and germination results will make it so much quicker and easier when you re-sow the various species or mixes.

How to sow and germinate microgreen seeds?

Always read the sowing information on your seed packets to see if there are any special sowing instructions. Most microgreen seeds do not require any special treatment before sowing, however, for some species with larger seeds or a hard seed shell, the germination process will be accelerated if the seeds are pre-soaked in water for 24 hours, or for at least 8 to 12 hours. During this process, it is beneficial to rinse the seeds in a colander with running water a couple of times.

Cover the bottom of your trays with about 3 to 4cm of your growing medium, and make sure it is evenly moist before sowing. The moisture in the soil will help very small seeds stick to the soil, and also keep them moist during germination. Flatten and level the growing medium with your hand or a small piece of cardboard, taking care not to over-compress the medium.

The size of the seed will determine the best method of sowing. Larger seeds can be pressed into the soil singly by hand, but small seeds are first measured and then spread evenly over the entire growing area of each tray, before being pressed gently into the soil. Remember, that while the seeding density should be thick enough to cover the tray, it should not be so thick that it inhibits air flow around the developing seedlings, as this increases the chance for diseases.

Most seeds benefit from an initial dark growth phase, and small seeds can be covered lightly with growing medium or fine perlite, or simply with damp paper towels which are removed as soon as germination has occurred.

If you do not have trays with clear dome covers, for faster germination you could create your own mini greenhouse by covering the trays with a clear or white plastic dome to keep the humidity in and help speed up germination. However, if it’s sunny and warm remove the covers occasionally to allow for ventilation, else you could hinder germination.

For larger seeds like peas and sunflowers it is recommended to put some weight on top of the seeds and soil after sowing for 2 to 3 days as this keeps the seeds in contact with the soil and helps with germination. Maintaining weight on top of the shoots during the germination process also facilitates the detachment of the seed hulls from the cotyledons. Some growers will simply stack the trays on top of one another for a few days after sowing for compression, and immediately the seeds start showing signs of sprouting, the trays are spread out to allow the seedlings to grow.

Keep the growing medium moist but not soggy until germination occurs by gently misting the trays with water as required.

How to care for microgreens after germination?

After the germination process is complete and the seedlings are actively growing, remove all covers from the trays to expose the sprouts to more light. Microgreens benefit from good exposure to sunlight or grow lights, and if the light is too limited you will see the shoots stretching out long, and leaning toward the available light.

At this point, besides the lighting, the only thing you need to do is to check that the seedlings have enough water. And if you are growing indoors, opening the windows to enhance air circulation is a good thing to avoid excess moisture around the leaves, which encourages the development of mould.

How and when can I harvest my microgreens?

Depending on the species and the growing conditions, microgreens may be ready to harvest within a few days or a couple of weeks. They are best harvested right before being used by cutting them off at soil level using a clean, sharp knife or a pair of scissors. Rinse them with fresh water before consuming, but be gentle as microgreens are delicate and easily bruised.

How can I store harvested microgreens?

Although microgreens are best used immediately they can be stored for a short time in a sealed container in the refrigerator. Their shelf life may be substantially reduced after washing, so if you are not ready to use them immediately, refrigerate them and wash only before they are used.

Which species are suitable to grow as microgreens?

Selecting the right microgreens for your personal needs, be they health related or just to enhance your culinary experience may seem a daunting task simply because the variety of plants suitable to grow as microgreens is so vast. For beginners, select those which are easy to grow and germinate quickly. To enhance the diversity of your harvest, opt for varieties with vibrant colours, and most importantly select those that suit your palate. Also, source your microgreen seeds from reputable providers who guarantee quality and consistency of supply.

Among the standard vegetable species used for microgreens, the most popular ones are those belonging to the Broccoli (Brassicaceae) family of plants, including: Broccoli, Radish, Cauliflower, Rocket, Cabbage, Kale, Kohlrabi, Mustard, Mizuna, and Cress.  These microgreens are characterized by a very short growth cycle and can be harvested 7 to 8 days after germination. All ‘cole’ crops, which simply means ‘stem brassicas’,  have a typical pungent taste which is primarily due to their content of glucosinolates - natural compounds that are considered to be anti-cancer, par excellence.

Other vegetable species commonly grown as microgreens include: Beet, Swiss Chard, Spinach, Amaranth, Lettuce, Chicory, Endive, Carrot, Celery, Fennel, Leek, Onion, and Cucumber.

Microgreens are produced by also sprouting cereals such as Barley, Oats, Wheat, Corn, and pseudo-cereals like Quinoa, Legumes such as Alfalfa, Peas, Beans, Fava Beans, Lentils, Clover, Chickpeas, and Fenugreek. Even species like Sunflowers and Flax are grown as microgreens.

Interesting microgreens are also produced using the seeds of aromatic herbs such as Basil, Cilantro, Dill, Chives, Cumin, Borage, Wild Chicory, and the common Dandelion.

In some cases, mixes of different species are used with the purpose of obtaining specific colour or taste combinations. If you wish to create your own mixes it is very important to balance the seed density, and also to check that all the seeds of the different species or cultivars will take the same amount of time to germinate and grow, so they can all be harvested together.

Which species are not suitable to grow as microgreens?

Some common vegetable crops like Tomato, Pepper, Eggplant, and Potato are not edible at the seedling stage and are therefore not suitable to produce microgreens because they contain alkaloids which at high levels are toxic for humans.

If you wish to use wild species to produce microgreens, it is very important to properly identify the plants from which seeds are collected, as many spontaneous species may look like edible plants, but could contain toxic compounds. Therefore, if you are not a plant expert refrain from using wild plants to produce microgreens. Also, you should exclude any species for which you may have an allergic reaction.

Which are the most popular microgreen species available in South Africa?

Alfalfa (Medicago sativa)

Alfalfa is one of the top 3 sprouts grown commercially and remains popular because it is known to be one of the highest sources of protein, and believe it or not, alfalfa sprouts or microgreens have more protein than a steak!  The seeds germinate and grow quickly and easily, and will be ready to eat within 5 to 7 days.

Brassica (Mixed Asian species)

Many blends of microgreens are available, and some of the most popular are unique blends of Asian leafy greens that include: Tatsoi, Pakchoi/Bokchoi, Mizuna, and spicy Mustards. As microgreens, you can start to harvest this blend from the dicot (seed-leaf) stage right through to the true leaf stage.

Broccoli (Brassica oleracea)

Broccoli is nutrient dense, and extremely high in antioxidants, with a mild, savoury flavour and delicious crunch. As a microgreen broccoli is ready to harvest from around 10 days, and is best if harvested just before its true leaf stage.

Pak Choi (Brassica oleracea)

Pakchoi, also called Bokchoi, is a delicious and easy to grow microgreen that has a slightly sweet and mild flavour, and is ready to harvest in 8 to 14 days.

Black Mustard (Brassica juncea)

Mustard is known to be high in cancer fighting carotenoids and flavonoids, and as a microgreen black mustard is nice and spicy, adding a touch of heat to your dishes, and the flavour gets deeper and hotter as it grows. For the highest nutritional benefit you can start to harvest at the 2-true leaf stage.

Mizuna (Brassica juncea)

This outstanding Asian brassica makes a superb microgreen which is very rich in vegetable proteins, iron, calcium and vitamins. The flavour develops as the little microgreen develops, and it can be harvested within 5 to 14 days.

Kale (Brassica oleracea acephala)

Mature kale leaves can be quite tough, but kale microgreens are tender and easy to incorporate into lots of different dishes. They are harvested soon after germination and usually before their true leaves have grown in, so it can take less than 10 days from germination to harvesting.

Chinese Cabbage (Brassica campestris)

Chinese cabbage microgreens are easy to grow and are packed with nutrients. They will be ready to harvest within 12 to 16 days, and have mild flavour that is a unique addition to any dish, and very popular in Asian cuisine.

Tsai Tsai Radish (Raphinus sativa)

These wonderfully spicy deep purple sprouts are a real winner if grown as a microgreen, adding both colour and flavour to any dish. As a microgreen they are very easy to grow and you can start harvesting at 7 days, in both the ‘dicot’ (seed leaf) and in the true leaf stage. The flavour changes as it moves through from sprout to true leaf stage.

Daikon Radish (Raphanus sativus)

As a microgreen daikon radish is super quick and easy to grow, and you can start harvesting from 7 days, in both the ‘dicot’ (seed leaf) stage as well as the true leaf stage. It’s nice and spicy, adding a real bite to any dish, and the flavour intensifies as it moves from sprout to true leaf stage.

Rocket, Arugula (Eruca vesicaria)

Rocket is an exceptionally popular microgreen variety as it is easy and quick growing, producing tangy, peppery leaves that are packed full of nutrition. Because it can be bitter when under 12 days of age, rocket is only used as a microgreen and not as a sprout.

Cress (Lepidium sativum)

Cress is an easy to grow microgreen that can be harvested in 8 to 12 days. It’s deliciously mild and slightly peppery flavour is great for salads, soups and garnishes, and because cress microgreens are nutrient dense they are often added to smoothies and juices for that extra health boost.

Lentils (Lens culinaris)

Lentils of all colours remain all-time favourites for both sprouting and growing as microgreens because they are really simple to grow, starting out as a sweet sprout and developing a deep, rich flavour as the leaves develop. As a microgreen lentils only take a maximum of 7 days before they are ready to be harvested.

Bulls Blood Beetroot (Beta vulgaris)

All beetroot can be grown as microgreens but bulls blood is in great demand with health conscious consumers who are looking for a carotenoid and flavonoid boost in their diets. It will be ready to start harvesting within 10 to 14 days, and for the highest nutritional value is best eaten raw.

Swiss Chard (Beta vulgaris)

Swiss chard and rainbow Swiss chard grown as microgreens make a very rewarding crop, and they provide great colour and flavour to dishes with their sweet earthy flavour. As microgreens they should be ready to harvest within 14 to 18 days.

Peas (Pisium sativum)

As a microgreen peas are a truly an exciting addition, best described as succulent, tender, and sweet, they provide great taste and texture to mini-leaf salads, or as a topping on cooked veggies. Depending on the variety you are growing, pea microgreens should be ready to harvest 10 to 14 days after germination, and are usually cut when the seedlings are anything from 5 to 15cm tall, depending on your taste and the variety grown.

Sunflower Sprouts (Helianthus annuus)

You will need to look no further than sunflower microgreens for a very nutritious, crunchy, delicious, and bountiful harvest. Their nutty flavour and firm crispness makes a wonderful additive to salads, or any dish that could do with a last minute lift or a light garnish. Whole sunflower seeds will produce a fast crop of nutrient dense baby leaves within 2 weeks.

Nasturtium (Tropaeolum majus)

Nasturtium microgreens are packed with essential nutrients, and are favoured by celebrity chefs for their delightful blend of peppery and subtly sweet flavours, making them an exceptionally versatile ingredient in a variety of culinary creations. As microgreens nasturtiums are easy to grow, and take around 21 days from seed to harvest.

Red Amaranth (Amaranthus cruentus)

Red amaranth is an exceptionally phytonutrient dense superfood with a host of reported nutritional benefits, and best of all, it is fast growing and can be harvested within 5 to 14 days, ensuring a continuous supply.

Coriander, Dhanya, Cilantro (Coriandrum sativum)

Cilantro microgreens are a staple in the culinary world and highly sought after by both home cooks and professional chefs for their unique, fresh citrusy taste and fragrance. Seeds germinate without soaking in just 5 to 6 days, typically reaching optimal size within 14 days. 

Basil (Ocimum basilicum)

Green or ruby red basil is a really superb herb that will add colour and zest to your microgreen mixes, and depending on the variety, should be ready to harvest around 20 days after sowing.

I hope this article has inspired you to grow your own microgreens at home. It’s fun, healthy and so easy to do.