How to Grow Microgreens

Growing microgreens at home is a fun and rewarding hobby that can enrich both your mind and your diet. There are various ways to grow microgreens at home but we'll focus on our two favourite methods: in soil, the traditional way, or using a hydroponic system. 

These instructions are generic in nature and apply to all varieties of organic microgreen seeds we supply. There are subtle differences such as the time to harvest or and how long to pre-soak the seeds, these details can be found on the product page for each specific microgreen seed.

To get started you will need the following equipment and supplies. Consider our ceramic wheatgrass and microgreen grow kit or wooden seed tray soil-based microgreen grow kit if you are missing the majority of these items. 

• Seedling tray - alternatively you can successfully use any non-toxic food-safe item which can hold a minimum of 1.5inches (3-4cms) of coco soil or compost

• Recyclable tray liner (optional) if using our wooden seed tray

• Coco coir soil mix

• Microgreen seeds

• Spray bottle

• Nutrients- organic trace minerals and seaweed powder

Step 1 – Pre soak

If specified on the product page instructions, pre-soak your organic microgreen seeds for the recommended time. Whilst this is not compulsory it will speed up germination and is as simple as placing your seeds in a jar with cold water. After the specified time, drain the water and rinse your seeds thoroughly. Smaller seeds such as broccoli, kale or alfalfa, or mucilaginous (gel-forming) seeds such as basil or rocket don’t need to be soaked.

Step 2 – Prepare your tray

When using a wooden seed tray indoors, we like to roughly line it with a recyclable material to prevent any water leaking out, tin foil or baking paperwork work equally well. For any other waterproof tray disregard you can skip this step.

Fill your tray with 1 to 3 inches of a coco soil mix- to do this place your compressed coco into a bucket and add lukewarm water. Once expanded stir in your trace elements and organic seaweed ensuring the microgreens are as healthy and nutrient-dense as they can be. Include perlite or vermiculite for a premium mix which will encourage excellent water absorption and drainage, ensuring a strong and healthy root system.

Tamp down the soil evenly but not firmly and mist with a spray bottle to moisten. Once flat and moist, not compacted or soggy, you’re ready for sowing.

Step 3 - Sowing microgreen seeds

When it comes to planting your seeds, feel free to find out what works best for you, however as a general rule try not to overseed. Each seed should have a one or two “seed length” gap around it so that it can breathe and grow tangle-free. Sufficient spacing also reduces the chance of humidity related problems such as mould.

Should you dramatically under seed, your harvest will at worst look a little anaemic or underwhelming, they will still be perfectly healthy happy plants and just increase the rate next time! At Grow Sow Greener we weigh our seeds prior to sowing so we know the correct rate once we hit the sweet spot for the container we are using at the time. A good even spread is what you are after.

Step 4 – Cover and press

Cover microgreen seeds with a fine layer of soil, or vermiculite for a cleaner harvest. This keeps the seeds humid for the germination process. Now mist with your spray bottle again. We find it beneficial to spray directly down thus firming the seeds into more contact with the soil.

Keep a humid atmosphere for your seeds to germinate. If using our ceramic wheatgrass and microgreen planters you can place the bamboo base directly on top to cover the seeds. Alternatively, place a second tray directly on top and apply weight. A few tinned tomatoes or another tray of growing microgreens will work fine. The weight not only forces strong root growth but also uniformity in crop height. Adding weight isn’t necessary however, but doing so will give your microgreens a professional look.

Step 5 - Germinating microgreen seeds

Set your tray somewhere where it will not get too hot or too cold and mist every 12 hours. Simply remove the lid and give them an even misting from your spray bottle before replacing. No other watering is required at this time.

Step 6 – Blackout and stretch

Not just forces of nature nutritionally, your germinating microgreens will start to lift the lift as they begin to grow. When this happens it's time to remove the lid and start the next step: blackout and stretch.

For long, elegant microgreen stems, withhold light for three to five days. This causes them to etiolate or stretch (the exact opposite of what you want your tomato or lettuce seedlings to do.). After a few days, uncover and water gently.

And again, like weighing the trays, this step can be happily omitted if you wish to keep things simple. Life is busy, time is short, and we guarantee you will have a perfectly acceptable tray of fresh nutritious living produce if like us, you sometimes just put them straight under light once germinated.

On the other hand, for those passionate, professional and slightly obsessive superfood growers who have an abundance of time to dedicate, feel free to implement the recommended steps as well as to experiment with such things as the relationships between texture, shelf life and humidity, or also the effect different wavelengths have on colour intensity or overall growth using our different LED grow lights. They truly are fantastic little things!

Step 7- Expose to light

Give your microgreens plenty of light. Natural sunlight during the warmer months is adequate however we highly recommend LED grow lights. By using artificial grow lights growth will be vertical rather than stretching towards the window. This results in less time and effort on your behalf and less wasted energy by the plant as you continually turn the tray to straighten them up. The main reason we love growing under lights is the ability to successfully grow in a dark north-facing room or apartment and enjoy fresh nutritious living greens throughout the darker winter months. Also, under indoor lights, your salad crops are now safe from garden pests.

Step 8 - Harvesting

Each variety of organic microgreen seeds will have a different time to harvest. Follow the specific guidance on the product page for accurate information however most varieties will be ready between 7 and 10 days. Before harvesting, move your microgreens to a cool area and aim to harvest at the same time you would transplant a garden plant- morning and evening. This aids shelf life and gives a better texture for eating. Simply cut above the soil level with sharp kitchen scissors and wash before eating to remove any soil contaminate.

For storage we recommend you refrigerate immediately after harvest and wash prior to eating. 

A quick note on mould. We recommend our coco soil or microgreen mats as they are sterile and don’t harbour spores, weed seeds or pests like your garden soil will, and store-bought compost might. You will probably notice a white fuzzy growth around the roots of your microgreens from time to time. This is perfectly normal and is actually caused by micro-roots searching for water; a useful indicator for when it's time to water your crop. Spray them with your mister and they will mostly disappear.

Many people including chefs and commercial growers prefer to grow microgreens on mats for the simple reason that they’re cleaner and easier to harvest and handle than their soil raised counterparts. Some varieties such as peas and sunflowers prefer to grow in soil but will handle a mat whilst some species such as beets are extremely challenging on mats and we recommend soil-based mediums for these varieties. In general, both methods work equally well and the choice comes down to user preference.

These instructions are generic in nature and apply for all of the varieties of organic microgreen seeds we supply. There are subtle differences however, such as time to harvest and whether to pre-soak the seeds or not. These variety-specific details can be found on the product page of each seed.

To get started you need the following equipment and supplies, consider our wooden seed tray and hemp-based microgreen grow kit if you are missing the majority of these items.

• Seedling tray alternatively you can successfully use any nontoxic food-safe item which can hold a 1cm thick microgreen mat.

• Recyclable tray liner if using our wooden seed tray.

• Hemp grow mats or coco grow mat

• Lab tested pathogen-free, GMO-free organic microgreen Seeds

• Spray bottle

• Nutrients - organic trace minerals and seaweed powder

Step 1 – Pre Soak

If recommended in the seeds instructions, pre-soak your organic microgreen seeds. Whilst not compulsory it will speed up germination and is as simple as placing your seeds in a jar and adding cold water. After the specified time drain the water and rinse thoroughly. Smaller seeds such as broccoli, kale or alfalfa, or mucilaginous (gel-forming) seeds such as basil or rocket don’t need to be soaked.

Step 2 - Prepare your mats and tray

Our microgreen mats are designed to fit the standard 1020 greenhouse flat size or full-sized English seed tray, which are the same size as our wooden seed trays. The mats are easy to cut into any size or shape you wish, you could even use a dinner plate base quite happily. When using our wooden seed tray, roughly line the tray with a recyclable waterproof material, tin foil or baking paper are usually convenient. You can submerge and soak the mats prior or simply spray generously with your spray bottle once in their tray.

Step 3 - Spread your seeds

Play around with this one, however as a general rule try not to overseed. Each seed should have a one or two “seed length” gap around it, allowing the seeds to breathe and grow tangle-free. Spreading your seeds also reduces the chance of humidity related problems, such as mould.

Should you dramatically under seed, your hydroponic microgreen harvest will at worst look a little anaemic or underwhelming, they will still be perfectly healthy happy plants, so just increase the rate next time. We like to weigh our seeds prior to sowing so that we know the correct rate once we hit the sweet spot for the container we are using at the time. A good even spread is what you are after.

Step 4 - Water and cover

Mist with your spray bottle again. We find it beneficial to spray directly down onto the seeds firming them further into mats fibres. Aggressive spraying from an angle can also cause seeds to be forced off the side of the mats. We also fertilise at this stage.

Keep the seeds humid by placing another tray directly on top and apply weight. A few tinned tomatoes or another tray of growing microgreens works fine. Adding some pressure on top not only forces strong root growth and uniformity in crop height but prevents some seeds such as peas from “levitating” above the grow mat, supported by their main root. This isn’t a major problem, however it does look funny and can complicate harvesting. The most important factor is to maintain a humid environment for the more exposed seeds.

Step 5 - Germinate

Set your tray somewhere where it will not get too hot or cold and check on your seeds from time to time. Mist whenever the mats appear to be drying out, or every 8 - 12 hours. Microgreens grown on coco mats require slightly more misting than on hemp.

Step 6 - Blackout and stretch

Not only forces of nature nutritionally, your germinating microgreens will start to lift their weighted lid as they start to grow. When this happens it's time to remove the lid and start the next step: blackout and stretch.

For long, elegant stems, withhold light for three to five days. This causes your seedlings to etiolate or stretch (the exact opposite of what you want your tomato or lettuce seedlings to do.) then uncover and water gently.

Again, like weighing the trays, this step can be happily omitted. Life is busy, time is short, and we guarantee you will have a perfectly acceptable tray of fresh nutritious living produce if like us, you sometimes skip this step and put them under lights once germinated.

On the other hand, if you’re a passionate, professional and slightly obsessed microgreen grower with an abundance of time to dedicate, feel free to implement the recommended steps as well as to experiment with such things such as the relationships between texture, shelf life and humidity, or the effect different wavelengths have on colour intensity or overall growth using our different LED grow lights.

Step 7- Expose to light

Give your microgreens plenty of light. Natural sunlight during the warmer months is adequate however we highly recommend LED grow lights. By using artificial grow lights, growth will be vertical rather than stretching towards the window. This results in less time and effort on your behalf, and less wasted energy by the plant as you continually turn the tray to straighten them up. The main reason we love growing under lights is the ability to successfully grow in a dark, north-facing room or apartment and still enjoy fresh nutritious living greens, even through the darker winter month.

Step 8- Harvesting

Harvesting microgreens grown on mats is a far easier and cleaner operation than harvesting those grown on soil. You can harvest the same way as you would with soil, by cutting above the mat with sharp kitchen scissors. Compost or brown bin the now used mat. Fast, simple and clean. Growing with our microgreen mats is our method of choice.

We recommend harvesting in the mornings or evenings which increases shelf life and gives a better texture. If you plan to refrigerate your harvest for later, please do so completely dry. We like to refrigerate our microgreens first, then wash them prior to eating. If your greens are a little damp at harvest, use a paper towel and allow them to air dry before storing in the fridge.

We don’t offer for sale any plastic trays or pots due to our plastic-free ethos, however growing stacked "tray in tray" microgreens hydroponically is popular and worth a mention. The process involves two seed trays, one with holes in, one without. The general method is the same as outlined above, except the grower places their microgreen mats in the first tray, with holes in the bottom. Then, using the tray without holes, they weigh down the seeds for the prescribed period of time before flipping the top tray over to create room for the plants to stretch.

Once you’re ready to expose the seedlings to light, remove the top tray and place your holed microgreen tray inside it. When watering, water into the bottom tray and allow the roots to hang down into the water below.

For storage we recommend you refrigerate immediately after harvest and wash prior to eating.

A quick note on mould. We recommend using our microgreen mats as they are sterile and don’t harbour spores, weed seeds or pests like your garden soil will, and store-bought compost might. You will probably notice a white fuzzy growth around the roots of your microgreens from time to time. This is perfectly normal and is actually caused by micro-roots searching for water; a useful indicator for when it's time to water your crop. Spray them with your mister and they will mostly disappear.

Some believe that no fertilisation is required for growing microgreens. This is technically correct if you harvest at the time the seed leaves open. Many Sprouts are harvested at this early stage and don’t require fertilisation.

However, we recommend organic fertilisation for your microgreens, as each seed has locked within it dormant energy which slowly degrades over time. Consider this energy a bridge between darkness and light. It’s only enough for the plant to germinate, grow a root, and open its baby leaves. After this, energy is derived from the sun, nutrition around the root zone and carbon dioxide in the air. Microgreens on the other hand are usually left a good few days after the seed leaves open, this allows photosynthesis and the production of enzymes, chlorophyll and other nutritious goodies to accumulate in their tissues.

We also want this experience to work for you. Sometimes we sow our seeds a little thin and benefit from an extra day or two for the crop to bulk up, other times we just plain forget about them and harvest late. Some varieties have amazing shaped and coloured true leaves (the next ones after the baby leaves) that are worth growing on for - gentle fertilisation gives more flexibility and helps you cover the bases.