In this blog, I want to discuss the difference between root hairs and mould. It's something many of you get confused over and often mistake a beautifully germinated tray of microgreens for mould.
That Fuzzy White Thing
When you first open your microgreens to light after the black out period, you might see fuzzy white hairs growing on the stems of the microgreens (picture below). These are actually root hairs and they are part of the plant's root system. In the early stages of a plant's growth, the root hairs come out of the roots of plants to help with water absorption.
To identify root hairs, it is important to know what they look like. Remember, root hairs are always white and they gather around the root. They radiate out from and are attached to the central root.
So this is a good thing to have and what it shows is that you have got a very good germination.
Root Hairs Growing On A Germinated Seed
That Spider Web Looking Thing!
Mould, on the other hand, is bad news!
Mould is a type of fungus that grows when certain environmental conditions are met. When you see mould growing on the medium of your microgreens, you need to address it immediately before the growth gets out of hand.
But what exactly does mould look like (because mould and root hairs can look quite similar to the untrained eye)? Unlike root hairs, mould can come in different colours like grey, black, dark green etc. The most important thing to remember is that mould will spread across your medium surface rather than on the microgreens itself. Sometimes they look like a spider web and at other times, they are dark and soggy looking.
Mould - spider web looking, dark, soggy
I Never Want Mould On My Microgreens!
No, no-one would. The best way to avoid mould is to ensure that:
- you don't over water your medium
- make sure your tray has good drainage so there is no risk of water log
- ensure that your microgreens are in an environment with good ventilation
- remove any foreign objects like twigs, leaves, etc from your soil before sowing your seeds
If you do find mould on your tray, there is still hope if it is confined to a small area of your crop. Use a small object like a wooden ice-cream stick and cut out the section contaminated with the mould and throw it out. Let the remaining crop grow as normal.
If, however, a large majority of your tray has been contaminated with mould, then it is best to throw the entire tray out and start over.
I hope this gives you a better idea of the difference between root hairs and mould. Happy sowing!