How to grow microgreens indoors is a fairly straightforward process which has highly rewarding results. In this guide I will be providing a detailed walk-through on the best way to grow your microgreens indoors.
Furthermore, this guide takes it for granted that you are interested in growing microgreens somewhere inside your apartment or house as most people do. This is what is assumed to be the indoors.
I have been growing microgreens indoors since 2015. The benefits are plenty. When I started out, it was stumbling in the dark until I was able to develop a system that works. I am happy to share that system with you which I hope will also get you going quickly.
I have two sections in this guide. The first section will be the equipment you will need to grow your microgreens indoors. The second section will then take you through the actual process of growing microgreens such as lettuce, sunflower or cabbage or whatever else micros to be grown out there.
Let’s roll…
Equipment for Growing Microgreens Indoors
In this section, we will now take a look at each of the pieces of equipment and material you will need indoors for growing microgreens…
1. Get microgreens seeds
Get your microgreens seeds. Keep in mind that it is recommended to use non-treated seeds when growing microgreens. Chemically treated seeds may be ingested together with your micros which is a potential health hazard. Many home growers of microgreens buy non-GMO seeds in bulk.
2. Get microgreens indoor growing trays
One of the most important pieces of equipment you will need to grow your microgreens indoors are grow trays. Grow trays come in different forms. Due to the popularity of microgreens, it is now thankfully possible to find commercially sold grow trays for microgreens. These come in different sizes but the standard ones are 10″ x 20″ with a shallow depth of 2.5″. An example is shown above as supplied by Amazon here.
Keep in mind that you will not necessarily have to use commercial trays although this is the norm for many people nowadays for convenience. I have often repurposed grocery punnets to grow microgreens of the type shown in this image.
The most important specs of your microgreens growing containers is that they should have shallow (but not too shallow) depth. This depth will hold some growing medium in the form of soil and deep enough to accommodate the roots. The shape or size of the container matters little.
Finally on trays, you will need a set of two trays to grow a single crop. One tray will have holes while the second tray will have no holes. The tray with holes is the one to be filled with soil and will sit inside the one without holes such that the one without holes catches the water when it drains. This prevents a mess indoors when growing your microgreens. Many people are now opting for commercial trays with pre-made holes for these practical reasons.
3. Get microgreens growing medium
You will also need some growing medium for your microgreens. Microgreens have the ability to grow on and in various types of growing medium. The most common or basic one is soil, good old native soil from your garden outside.
You can also grow microgreens indoors on materials such vermiculite, grow mats/pads, potting mix or seed sprouters. I recommend good old soil which, by the way, need not be fertilized. Microgreens get their nutrients from the seed and less from the growing medium.
4. Get LED lights
One of the most important requirements on how to grow microgreens indoors is an artificial light source. The type of lights to use for growing microgreens indoors are typically high output LED lights. LED lights replace natural light source which is the sun.
LED lights work better than the sun because they produce high intensity light which is not destructive to the delicate microgreens. These artificial lights encourage your microgreens to grow rapidly upwardly towards the light source.
Your LED lights will be placed right above your microgreens tray as shown in this example. You can find commonly used lights here.
5. Get microgreens growing stand or shelf
To grow your microgreens indoors, you will also need a shelf or stand where you can place your grow trays. The LED lights mentioned above will be attached to the top of each shelf above the tray. If you have an already existing shelf indoors this should also work well if lights are added.
6. Grow your microgreens in aerated location
Microgreens require unhindered air circulation to do well. If air circulation is limited, they may develop devastating mold which often leaves the crop a right-off. Ensure that you place your microgreens growing stand in a location allowing free air flow all the time.
How to Practically Grow your Microgreens Indoors
Now that we have all the equipment required, let’s move on to start growing the micros.
Step 1 – Prepare your microgreens growing soil
As mentioned earlier, native garden soil will work to grow your microgreens. All you need to do is to sift the soil to remove any debris and particulates. The soil should become fine after the sifting.
Put the finely sifted soil in your growing tray with holes. Fill the tray with the soil leaving 2mm or 3mm space on top.
Step 2 – Water the soil in the tray
Once you have your tray filled with fine sifted soil, let it sit in the second tray without holes. Now proceed to water it thoroughly using a fine spray to avoid disturbing the soil.
The bottom tray without holes will catch the draining water from the top tray with holes and soil in it. Mind that we have not yet planted the seeds. We are just watering the soil at this stage.
Step 3 – Plant the microgreens seeds
After giving the tray with soil a thorough watering, it’s time to plant the microgreens seed. Spread the seeds evenly but densely across the top tray with soil in it.
Use your open hands to gently press the seeds so they make contact with the soil. We are doing this because we are not going to bury the seeds under any soil at all.
Step 4 – Water the planted seeds one more time
After pressing the seeds gently to make contact with the soil, you are done planting. No need to cover the seeds with any soil. Now proceed to give a quick spray the planted seeds. We use a fine spray to avoid disturbing the seeds.
Step 5 – Cover the planted tray to create a dark environment
After the quick water spray, cover the tray to create a dark environment. If you have an extra tray, make it sit on top of the tray with the seeds pressing the seeds down. You may alternatively flip it over to create a Dom. In both cases your tray with planted seeds should be dark inside. Place the tray in a cool dark place such as under the kitchen sink or a store room. The planted seeds will not require any watering until they germinate and are taken out of the dark.
Step 6 – After germination place tray under artificial light
After some 3 to 4 days, your planted seeds should be germinated. At this stage the covered tray may be opened and placed under the grow LED lights. The microgreens will almost immediately (over hours) respond to the LED light by turning green or any other natural color of your microgreens. This is an indication that they are responding to the light.
You may also water the microgreens by pouring water in the bottom tray without holes so that water sips into the top tray through the holes on the bottom (see the concept here). This is a smart way of watering microgreens that minimizes risk of your microgreens developing mold and other problems.
Step 7 – Harvest at about 10 days
Your indoor microgreens project is going well. Now you can look forward to harvesting your micros at about 10 days depending on the type of microgreens you are growing. The rule of thumb when it comes to harvesting your microgreens, in most cases, is to harvest before true leaves appear.
True leaves are the leaves that shoot after the seeds have germinated. They tend to be the third leaf on the microgreens. When these start appearing it’s getting late and the microgreens are likely to start turning bitter.
So this is it, this is my guide on how to grow microgreens indoors. Go ahead and start enjoying those micros. Happy gardening!
