How to Spot and Treat Mould in Microgreens

Fine cobwebs between the leaves and the stem is a sign that you are growing mould in your microgreens.  Don’t be confused with the fine hair which is growing on the stems. These are called root hairs and are bright white and always appear to congregate around the root itself. Remember, they radiate out from, and are attached to, the central root. Mould on the other hand can be many different colours including grey, black and even blue. Mould will never be as bright white as the root hairs.  They will be more greyish.  Do the watering test.  Spray gentle water from above the area that you think is mould.  When they are root hairs the fluffiness will disappear.  If it stays fluffy it will be mould.

What are the causes? A warm and humid environment, poor air circulation and moisture are the key ingredients for the mould spores to grow and thrive.  Mould in your microgreens is mainly caused by too much humidity. This can happen when you are continuously giving them too much water or if they are placed in a humid environment where they are not getting the right temperature and enough light. 

Yes you can remove the mould!  When spotted remove all the visuable mould with a soft cloth. Wipe gently across all the microgreens I know it is challenging.  Try not to break and stems.  Remove dead and yellow leaves. Try to remove

Continue by removing all dead and yellow leaves and clean out the tray so you only have the healthy microgreens left. It’s important to go through the entire tray, leave by leave, to ensure you remove any mold.

You can also use a mix of Hydrogen Peroxide (3%) and water and spray gently over the grow medium . Use about 2 tablespoons of Hyd Per with half litre of water in a spray bottle.

Do not overwater the microgreens and try to reduce humidity by using humidifier if you have a lot of damp in the room and open the windows to promote  airflow. Very important to keep the space where you grow your microgreen in a dry condition and with good airflow.

When whole crop is affected, get rid of it and start all over again.