How To Prevent Mold Growing On Microgreens

<a href=''>Jon Smith</a>Jon Smith
April 5, 2021

It has happened to most of us. About six days into the microgreens growing there is mold growing along with the nutritious and scrumptious microgreens.

This really puts a bad taste in your mouth (pun intended) and makes you want to stop growing microgreens.

Don't stop growing them, let's just learn how to prevent mold from growing on your microgreens.

Microgreens are so good for you why would you ever stop growing them?

In this article, I will share with you my top tips to prevent mold on your microgreens.

Microgreen Root Hair Vs Microgreen Mold

Sometimes it is a bit tough to distinguish between root hair vs mold but if you look close enough you can see how mold is stringy and not just on the plant.

Root hair is attached to the plant root and bottom stem. It is more clear and easier to spot.

Microgreen Root Hair Vs Microgreen Mold
Left we have root hair vs right we have mold. Can you see the difference?

Is It Really Mold On Your Microgreens

Mold is a stringy growth that will appear along the stem of your microgreens. It is important to be able to distinquish between mold and root hairs which are typical for most small plants.

Root hairs will form at the bottom of most microgreens and look really similar to what mold would look like. Here is a picture of mold and root hairs side by side to help you determine the difference between root hair and mold.

The best approach to getting rid of mold from your microgreens is to prevent it alltogether. You can still harvest a molded microgreen crop bypassing the mold areas of the tray but I do not recommend that.

I prefer to scrap the entire tray because there could be mold spores hanging around other areas of the microgreen crop.

Just scrap the entire tray and use the prevention methods below.

Prevent Mold From Growing On Microgreens

I have a large list of microgreen mold prevention methods that you should incorporate into your own microgreen growing process.

It is important to prevent mold rather than try and beat it. Even the easiest to grow microgreens get mold if not handled properly, but let us prevent it so that it is not even a problem for you.

Bottom Watering

This is probably the best way to ensure you do not end up with a moldy microgreen crop. Bottom watering keeps your microgreen plants dry but also ensures that they are getting the water they need from the bottom tray in your microgreen setup.

Watering Less

Most people think that they need to keep watering their microgreens to ensure their health and high yields. This is not true and could cause mold to form on your microgreens.

Overwatering also causes roots to be soggy and could cause root rot or root mold.

I typically water my microgreens once per day 1/2 of a cup to 1 cup.

It is best to feel the soil with your finger to decide if you need to water or not and how much. If your soil or growing medium is dry then use 1 full cup of water. If it is still moist then you likely do not need to water at all and I suggest checking back in few hours.

Microgreens are extremely hardy and it is better to water less than overwater your crop.

Use Trays With Holes And Without

This method uses two trays to grow your microgreens. You will use the top tray to house your soil and seeds. The bottom tray is used for watering.

Use Fans To Circulate The Air

Prevent mold from growing by keeping your microgreens surrounding air circulated. I do this by placing a fan a few feet from them and blowing lightly to the space around them.

Do not point the fan directly on your microgreens.

Disinfect Your Trays

After every microgreen crop I will clean my trays and soak them in a bath of alcohol and water. After the bath I will spray them down with a mixture of hydrogen peroxide to further sterilize my trays.

Keeping everything clean will ensure you have a healthy and mold free crop.

Swap Out Bottom Trays

I like to swap out my bottom trays every other day and sometimes daily for microgreens that require more water. This will ensure that your water is being stored in a clean tray giving your microgreens the cleanest environment possible.

I have many extra trays not in use just in case needed. Check out our best microgreen trays guide here and get yourself a few extra unused trays for your microgreen growing setup.

Disinfect Your Seeds

You can disinfect your seeds by soaking them in a hydrogen peroxide bath just like your trays. This is not harmful to your seeds but actually very beneficial to them.

Soaking seeds for a few minutes will prevent mold later on when they are germinating.

Disinfect Your Hands

Washing your hands is crucial. Clean hands help prevent mold and other issues with your crop. Keep your hands clean while handling your microgreens since it is food.

Seed Density Preventing Mold

If you use a lighter seed density you will less likely have a mold issue. When combined with the prevention methods in this article you will undoubtedly see any mold on your microgreens.

Seeding too densely will prevent proper airflow causing wet conditions to stick around which is the perfect breeding ground for mould.

You want adequate airflow around your microgreens so less is more I often say.

Control The Humidity In Your Growing Room

If you have a special growing room for your microgreens I recommend purchasing a dehumidifier to ensure that your humidity levels are optimal for your microgreens.

You can also purchase a humidity test to ensure your humidity is in perfect range.

Proper Lighting

I like to use LED lights that emit the proper range of light needed to grow microgreens. I like the 5k kelvin range and this will add to the prevention of mold growing on your microgreens.

Be sure you have 10 to 12 hours of light daily for your microgreens. Mold prefers a darker environment so be sure that your microgreens are getting enought light and warmth from your lights.

Also, keep your lights close around 6 to 14 inches above your microgreens depending on the wattage of your light. More wattage means you can have them further away.

How To Remove Mold From Microgreens

Let me just start this by saying you should scrap the entire tray of microgreens if you find even a small section of mold. This is why I tend to steer clear of sprouts.

Mold can be harmful to your health and accidental ingestion could be detrimental. It is best to avoid this by scrapping the entire tray and using best practices as outlined in this article in the next microgreens crop.

You can remove portions of the crop or spray with hydrogen peroxide to kill the mold but again this is not recommended. Soak your seeds in a peroxide solution and start with peroxide which is safe for your plants and you to prevent mold and you will be better off.

A Clean Microgreen Grow Room

It is best to set yourself up for success. Keeping a clean grow room is important to the success of your microgreens.

I recommend cleaning after every harvest. Alcohol and hydrogen peroxide are the best cleaning solutions available for this type of cleaning.

Clean your grow racks, lights, trays, watering containers, and harvesting tools. You want to clean everything that comes in contact with your seeds and microgreens.

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How To Prevent Mold From Growing On Microgreens
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About The Author
I have been growing microgreens for myself and others for quite some time now and I absolutely love the process.

Even more I love spreading awareness of an amazing crop that has so many nutritional benefits for our bodies which improve our overall health and wellbeing.

Jon Smith

Copyright 2021 All Rights Reserved!

As an Amazon Associate I earn from qualifying purchases.