How to FIX / REMEDY Microgreens MOLD (Safe & Fast)

You may have been startled in the past to see mold growing in your microgreens and not known what to do. Stay tuned because by the end of this post, you will know exactly what to do when you see mold and how to remedy it quickly and safely.

At this point, I rarely encounter problems with mold, but every once in a while I see a little bit growing in a tray. I never sanitize my seeds but have instead kept my business resilient to mold by using tactics and techniques that I mentioned in my previous Microgreens Mold Videos:

Microgreens MOLD or ROOT HAIRS & How To Tell The Difference?!

What ACTUALLY Causes Microgreens Mold? (The TRUTH)

How to PREVENT Microgreens MOLD (Problem SOLVED)

Even though I don't experience these problems anymore, I still keep a few tricks up my sleeve just in case I happen to see some mold in a microgreens tray. The best way to combat mold is to never have it show up in the first place. Even if you're super careful and utilize the advice that I gave in my previous blog posts, chances are you will still encounter mold from time to time, so let me share with you right now what to do in case mold does appear.

One of the most common places you will see mold is right after germination because the trays of microgreens have been in an environment that has high humidity, high temperature and low airflow. This is the same climate that mold thrives in, so it's no surprise that you can experience mold when taking trays out of germination. When I see this happen, I actually do nothing different… I simply move the trays out of germination under the lights, and make sure to top water right away right over the mold and the sprouted seeds. This top watering actually damages the mold colonies and now that the trays are in your main grow room under lights, proper airflow will prevent the colonies from forming again.

If you’re grow room has proper environmental controls, specifically airflow, chances are this technique will do the trick. If the mold happens to bounce back and you still have an issue, there are two other tactics you can use to further combat this problem.

The first is by simply removing the clump of soil where the mold is growing and then adding more soil to fill in the hole. You want to add a little extra to go above and around that area so the mold can't keep spreading across the surface of your growing medium. If you catch the mold early when there is only a small section of damage, chances are you will be able to save the tray and have a decent harvest later on.

The second method is using some sort of sanitizing agent, like a food grade hydrogen peroxide, and spraying that over the problem area. I've also heard of people using a diluted vinegar solution and using it in the same way. Don’t use something like bleach because obviously you and your customers don’t want dangerous chemicals anywhere near the microgreens.

I use a product called ZeroTol 2.O which is a food grade hydrogen peroxide that is certified for organic growing (OMRI Listed). I typically use this product on an ongoing basis for sanitizing trays and equipment, but it can be used to remedy mold and fungus as well. When using it, just be careful because it can burn your skin in its concentrated form straight out of the jug. It must be diluted with water before use, so wear protective gear (gloves at the very least) and pour it carefully. Also, the price may seem expensive, but I’m still using the same jug of Zerotol that I purchased three years ago. It comes in a concentrated form that you dilute, so it will last a very long time, even at a commercial scale.

The last way to combat mold is to simply harvest above it. I sometimes get mold in my wheatgrass just before it's ready for harvest, but it's manageable and stays low, towards the base of the plants. What I do is I just harvest a little bit higher so I can avoid the mold.

So there you have it, four different ways that you can fix and remedy mold when it appears in your microgreens!

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