• On The Grow®, LLC

How to Grow Microgreens Guide - On The Grow® Style

Updated: Jan 3

On The Grow's Rambo Radish Microgreens Growing
On The Grow Farms Logo and Tag Line Do You Be-Leaf In Magic? Copyrighted

Okay, you're ready to dive into the amazing world of growing microgreens at home or for the purpose of starting a microgreens business of your own - to learn how to grow these amazing greens, you can start by reading this blog which will help you get the gist of it, but if you really want to learn EVERYTHING we have learned from 2019 to 2021 we highly suggest our book "Becoming a Microgreen Master" - it's basically the ultimate Microgreen Growers Manual.

But any who, let's help you learn the basics! Before we can start growing beautiful microgreens like these Speckled Pea Microgreens,

Speckled Pea Microgreens growing in Microgreen Trays next to eachother by On The Grow
"Photo of Speckled Pea Microgreens - On The Grow"

you first need to choose how you are going to grow and determine what materials you will need to start growing with. Then we can walk through each step of the way to get you growing healthy, happy and abundant trays every time. We hope that this article can become your go to guide on how to get amazing grows, so lets get started!

The first thing we are going to do is select a growing style! Here at On The Grow, LLC, we love basically all growing methods! As long as it is something you enjoy and produces happy microgreens, we are all for it!

If you're growing microgreens in soil, they will have access to all the minerals and organisms in the soil, immediately. Using soil is a tried and true method for growing and will generally provide really solid results, depending on the soil used. When it comes to growing with soil, we prefer to use a soil that doesn't have chunks of wood or other large debris while having good drainage. We usually stick to "seedling mixes" or "potting mixes" if no seedling mixes are available. A popular soil choice within the commercial growing community is ProMix+ HP Biofungicide Mycorrhizae.

We love to grow microgreens "hydroponically" which is basically adding minerals to water and giving that to the plants instead of using a soil that has minerals added already. To grow hydroponically, you must...

First select your grow medium, we prefer Coco-coir because it gives us such great results and we have more control over it because we can choose to boost our plant growth by adding our own nutrient's. What makes it even better is even without nutrient's Coco-coir grows microgreens perfectly! Coco-coir is made from the outer-husk of a coconut and is a great sustainable option for growing. We buy our Coco in compressed bricks and expand them with water when we need it!

Microgreen Grow Mediums made from Hemp, Cocoocoir, Biostrate and Coco Mats placed in 1020 Microgreen Trays for growing Hydroponic Microgreens
"Hemp, Coco-Coir, Biostrate and Coco Mat for Hydroponic Microgreens"

Next step is to select your Trays to grow in. We use a 3-tray method that consists of 2 shallow no holed 1020 trays and 1 shallow slotted or mesh 1020 tray. You can also get away with using 2 trays (one no-holed tray and one mesh or slotted tray).

If you are wanting to get started without buying trays, you can practice growing on plates or old food containers to hold the grow medium and seeds. Click here to see our video on this!

Three 1020 Microgreen Trays from Bootstrap Farmer demonstrating the On The Grow How To Grow Microgreens supplies needed for growing Microgreens
On The Grow's three Tray Setup for growing Microgreens using BSF Trays

Can't decide if you should use a Mesh tray or a Slotted tray? Usually we will use Mesh Trays whenever growing on a Hydroponic Grow Mat as the medium, because the roots can latch onto the mesh holes making it easier to harvest later. If we are using Coco-coir or a Soil medium we like to use a Slotted Tray, that way we don't loose to much medium through the mesh holes...but mesh trays also work great for Coco-coir and Soil too.

Tip- keep the coco or soil moist when using a mesh tray so it doesn't fall through.

Lastly choose your seed. Some great varieties for beginners are Broccoli, Purple Kohlrabi, Turnip, Radish, Mustard, or basically anything within the Brassica family. These crops grow abundantly and are easy to grow especially for new growers.

Mixture of Microgreens Seeds from On The Grow farms favorite bulk seed supplier Trueleafmarket - Radish Microgreens, Broccoli Microgreens, Spicy Salad Mix Microgreens Seeds

Tip- we have tons of Full Walk-Through Grow videos available on our YouTube (by clicking here) that can help guide you through growing different varieties for Free and with ease! Also be sure to check out our Downloadable Grow Guide on our website's main page to learn about how much we use of each seed and our average grow times! If you're looking for a seed company, a reliable seed source is TrueLeafMarket , which is one of our go to seed company choices.

Now that we have our materials it is time to start growing!!

Slotted 1020 Microgreen Tray on top of a no holed 1020 Microgreen Tray

First, take one of the no holed trays and place your Slotted or Mesh tray on top of it, so they fit together like the picture on the left... (there's a black tray under the green)

Slotted 1020 Microgreen Tray with filled with the Grow medium Cococoir for growing Hydroponic Microgreens

....Second, fill the Slotted or Mesh tray with the grow medium of choice. Typically, we use about 6-8 cups of coco-coir per 10x20 tray. That way it fills the tray enough to cover the area, but the grow medium is still just below the rim of the tray. Evenly distribute the grow medium in the tray so that you have a nice leveled surface! It does not have to be perfect, just make sure you do not have a lot of low or high spots as it will cause problems later. If you run into clumps of grow medium, try breaking them apart some.... (You can also use another tray to press it down even)

Grow Medium Cococoir with Basic Salad Mix Microgreens Seeds showing How To Grow Microgreens using the On The Grow method

...Third, take your desired seed and evenly spread the seed on the tray. Typically, if we are seeding a 10x20 tray of Broccoli Microgreens, we will use 25grams of seed, but if we are using a 9.5x11.75 tray will cut the sow weight in half. Keep in mind that the seed amount will change depending on the Microgreen varieties you pick. You want the seeding to be dense, but not so densely that you restrict the air flow between the plants. If a tray is over-seeded, it will have a much higher chance of developing problems with mold! But like I stated before, you are in luck because we have our wonderful Grow Guide here on our website and Full Walk-Through Grow videos on YouTube to help you easily figure out how much seed to use for a lot of different varieties of microgreens!! **When it comes to seeds with a harder shell, like Beet Microgreens or Swiss Chard Microgreens will put a thin layer of coco-coir across the top of the seed as well to help with the germination and seed hull removal. Check out our video on How to Grow Swiss Chard Microgreens if you're interested in the full process!

You have seeded your first tray, Congratulations! It is now time to give your seeded tray a light mist with either a spray bottle or a water hose that has a spray attachment set to the 'mist setting'. Making sure not to over-saturate it (you don't want puddles or water pooling in the bottom of the tray!) but give it enough water so the seeds can happily germinate!

On The Grow, How to tell when your Grow Medium and Microgreens seeds need more or less water during germination.
"Left side shows Coco-coir when the medium is properly hydrated. Right side shows when Coco-coir is under-watered"

After watering, you take your second no-holed tray, place it on top in the same orientation as the other trays (that way it makes contact with the seeds) then place some weight on top of that tray before you place it onto a dark shelf to germinate.

How to setup your Microgreens Trays for the Best Microgreens growth and germination

You may be asking "Why do we add weight?"... The reason why we add weight is for a couple reasons. Adding weight helps you get even germination across the tray because of the pressure it puts on the seedlings, while pushing them into the moist grow medium. The weight also helps remove the seed hulls by providing resistance which is extremely important, especially for crops like Sunflower Microgreens. However, there is a limit to how much weight you should use along with some varieties that do not do well with added weight, like Red Garnet Amaranth Microgreens. For most crops we will use between 15lbs to 7lbs of weight. Then for the more delicate crops, will use just the empty top tray to act as the "weight". If you feel confused on which crops need added weight and which crops only need an empty tray, we have that information listed on our grow guide! (We've found that all crops will grow without weight, just not as well as with-weight.)

Alright, we have gone through the steps for germination. Now what?

Microgreens germinating under weight on a dark shelf

What you will want to do is, twice a day for the first couple days lightly water your seeds in the morning and night with regular water, that way they can continue to germinate. After each misting be sure to place the top tray and weight back on top before placing them back on to your shelf.

On The Grow's Cilantro Microgreens emerging from Hydroponic Grow Medium Coco-Coir

After a couple of days, you will see that the crop has germinated! Keep in mind that germination time is different for each variety. Some happen within 1 day and others take up to 3 days.

There are some crops that can take up to 15-20 days to germinate, and we avoid those crops. Ain't nobody got time for that.

Whenever 1-5days has passed, you may see that your tray has germinated well (you want plants that have removed the seed hulls)! That means it is time to move into the next step which is Black-Out! But before we move into Black-out, below are a few tips if you've run into anything unexpected during your grow.

Tip 1 - your seeds may take more or less time to germinate depending on the grow medium you selected and the climate in which your growing in. We know that we get the best germination when we use Coco-coir and grow in our set Climate of 75-85F with a humidity of 50% or lower. When we have grown in temperatures below 75F, we notice slower germination and growth. Something else we highly suggest is having good airflow, as this will help with preventing Micro-Climates on the shelves created by heat from the lights and will reduce issues with Mold. Every shelf in our grow space has one of these AC Infinity fans per-shelf, and if your curious on how we setup our grow racks be sure to check out our video (click here).

Tip 2- Something you might notice now that your seeds have germinated is some fuzzy white stuff, most people confuse this with mold… but do not worry! Those are called "Root Hairs" which are just part of the plants root structure. If you picked a seed like Radish or other Brassicas… they tend to form a lot of them. How you can tell Root Hairs apart from mold is, by looking to see if the "fuzzy stuff" is attached to the plant? Or, is it attached to the seeds and/or grow medium? If it is attached to the plant, then it's most likely Root Hairs. However, if the white strings are coming off of the unopened seeds, seed hulls or grow medium and has a Spider Web or Spore look to it… then that’s mold and you may have over watered or seeded to densely. No worries though! As long as you caught it before it goes crazy, your good. Try watering a little less on your next watering, and you can spot treat the mold with a 2tbs 3% Food Grade Hydrogen Peroxide per 1 Liter of water mixture to combat the issue! Good airflow can also help reduce or control mold.

Microgreens Tray reveresed for Black-out showing How to grow Microgreens