As seen in: Issue 20

Korean Natural Farming: Feed Ferment To Your Plants


If you’re looking to get into a more genuinely organic form of farming, then you are in the right place, my friend. Korean Natural Farming puts the ‘fun’ in the fundamentals of organic gardening. Okay, that might be an embarrassingly weak pun, but you know what I mean.

Woolen Eyes

Stepping into the realm of true organic farming is an exciting prospect, one that puts you back in touch with the natural world. The simple definition of organic is a funny one though; does a fancy- looking stamp from a governing body mean it is organic? Some would even argue that if you are feeding your plants from a bottle you bought from a store, then you are far removed from being truly ‘organic’ (i.e., you cannot manufacture ‘natural’).

Then, of course, you have the problem of how marketing teams come up with descriptions for their brands to appear and sound organic, further muddying the waters along the way. Using terms like ‘bio-synthetic’ or ‘all-natural ingredients’ to make you think one thing, when in fact, it’s another. It is not just using words cleverly here and there in advertisements either; entire brands are built on the premise of all of their products being organic. Often, one or two of them may genuinely have an organic stamp, but the rest of the sometimes-extensive lines do not, and they are disguised as salty wolves in some organic sheep’s clothing.

Bottles are for Babies

You can bypass the marketing smokescreens (and high cost) and make yourself inputs that are more ‘organic’ than anything you will find in a plastic bottle in your local hydro shop. Fermenting organic material is a fantastic way to unlock the naturally occurring nutrients, aminos, and enzymes contained within the plant material. It is the basis on which a lot of commercial additives are built upon; many of the costly ‘boost’ products are simply a natural plant ferment, refined for mass production.

It is relatively easy, and probably the first of everything that KNF has to offer that you should try. The entire process takes roughly a week, and you can easily integrate it alongside whatever organic regime you may already be doing. Referred to as Fermented Plant Juice (FPJ) or Fermented Fruit Juice (FFJ), you can either ferment plant material directly, (i.e., leaves, shoots, buds, and flowers) or you can choose to use fruits instead. Of course, there is somewhat of a difference between which material you use to ferment, and therefore, when and how they should be used.

SFF (Start Foraging Fools)

Before deciding what to ferment and how to use it, you should first think about nature and the materials that you have to work with. The natural farming purest will argue that the material you are fermenting should come directly from the natural world around you. However, for some of us city-dwelling natural farmers, this isn’t always easy. If you do head out into the natural world, try to go at the crack of dawn; the water storage in the plant itself will be at its highest point, and the beneficial bacterial content should be a lot greater at this time of day.

Purchasing from stores does give you access to a wider range of material to ferment. However, keep in mind you will be missing most of the natural bacteria, as the produce is usually cleaned and treated before being put on the store shelf. So, in a nutshell, plants and fruits harvested directly from the natural world are the most ideal. Only in the event of inaccessibility should you go to your local organic farmer’s market, or worst-case scenario, the supermarket.

What to ferment and why

Do not only think of ferments as a source of nutrients. The hormones, aminos, and enzymes you extract in the process are just as (or even more) crucial to capture and use correctly. But what does that mean to the process as a whole? FPJ and FFJ are actually very similar but have a slightly different approach.


In terms of an FPJ, it can be beneficial to select and ferment sections of a plant that relate to the stage of growth that your plant is in. For example, if you are in a vegetative stage of growth and want to encourage branching and more shoot growth, harvest the side branches from a vigorously growing plant. These side branches will naturally have a higher level of the type of nutrients, hormones, and aminos that promote side-branching, and will likely pass that quality on to the crop you are feeding. Harvesting the buds and young flowers of various crops will mean a high-level of flowering hormones in the ferment you make – ideal for use on a crop during its flowering cycle. Finally, harvesting and fermenting the roots of dandelions, for example, should be great to use in the vegetative period, encouraging rapid and healthy root production.

Dandelion Root from Harvest

Dandelion Roots, from harvest to Fermented Plant Juice (FPJ), great for use during the vegetative period.


Fermenting fruits is a very similar process and mindset, but there is a slight difference. The ripeness of the fruit you are fermenting impacts the stage in which you want to be using it. Under-ripe fruits should be fermented and applied toward the early flower cycle. Use ripe fruits towards the middle of flower, then over-ripe fruits towards the end of the cycle. The game aims to tailor the ripeness of the fruit to the stage of growth you are feeding. Nutrient-dense fruits, such as bananas or mangoes, can be a wonderful source of elements for a heavy-feeding fruit plant, and an excellent addition to a KNF regime.


Hops Flowers, from harvest to partially Fermented Fruit Juice (FFJ).

Hannibal was onto something

One of the most effective ferments you can give to your plant is the actual crop you are growing. It will already contain everything that exact plant needs and/or uses in a completely organic form. For example, ferment some tomato plants to use as feed for another tomato plant. The resulting ferment will contain elements unique to that plant and crop, offering so many things the plant requires and would otherwise spend energy creating itself.

OK, I’m game. How do I do it?

To create your own ferment, you will need:

  • Some weighing scales
  • A glass mason jar (or another appropriate container)
  • Some plant/fruit material
  • Natural dark brown sugar
  • A Strainer (cheap way = women’s tights; pro-way = fruit press)
  • Optional LAB

Step 1

Weigh your plant material. Stick to one type of material at a time. (i.e., do not combine fruit and leaves/flowers in a single ferment – do them separately).

Step 2

Weigh out the same amount of brown sugar. However, sometimes (particularly when making FFJ) you may need to use more sugar if there is a lot of juice from the material. This is very much a ‘play it by ear’ situation.

Step 3

Mix it all until the sugar is evenly distributed around the plant/fruit material (add LAB at this point if you are using it). The sugar then begins to draw-out the juicy plant goodness through osmotic pressure.

Step 4

Fill your storage container with the mixed material, pressing the lid down to slightly compact and level it off. Add a small layer of pure sugar to the surface to act as both a cap and slight weight.

Step 5

Cover with a breathable lid. Use a rubber band to attach some greaseproof paper or paper towel.  DO NOT SEAL THE CONTAINER WITH AN AIRTIGHT SEAL – IT NEEDS TO BREATHE!!!

Step 6

Leave it for 5-7 days, sometimes longer. The ambient temperature of the environment will impact the speed of fermentation, but generally, in a normally cool and dry storage area, 5-7 days is adequate.

Step 7

Separate the liquid material that has been produced. This is either a case of squeezing it out through a pair of women’s tights or by using a fruit press to make sure you get every last drop of goodness out of it.

Step 8

Place in a storage container with a breathable lid like before.

Step 9

Use it! Usage guidelines are fairly broad, with each ferment, of course, having its own unique characteristics. Anything from between 1-2.5ml per liter will do you proud. Obviously, increase or decrease accordingly as your plant develops.

Forever blowing bubbles

One thing you will need to keep an eye on is any bubbling that begins from your liquid. If it starts to bubble, you need to add more sugar. It’s a good thing because it means it is highly active, but also bad because the more it bubbles, the more it degrades. The extra sugar acts as a drying agent within the liquid and reduces the availability of water to the fermentation process. In a super-active ferment where no amount of sugar will stop the bubbles, then you can resort to pouring in some high percentage alcohol, like vodka, which should stop it in its tracks. Then, of course, you can pour one for yourself as part of the self-congratulatory process.

That is pretty much it. Of course, this is a very brief guide to ferments; the ins and outs could be discussed at length, but hopefully, this gives you a good idea about how to build it. It is an extremely cheap and easy process to go through, and producing your own additive to use alongside your existing organic regime (or as part of the full KNF suite) is extremely satisfying.

Besides being fun to do, many organic growers who have converted to KNF have noticed a significant increase in the aromas, flavors, and effects of their final crop. Whether this is a placebo effect or not is hard to prove, but with similarly consistent testimonies seen by natural farmers from all over the globe, it is one that is hard to argue. Plus, it did make for a catchy title…

Read more articles from the Korean Natural Farming series:

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  • kevs (UK) says:

    Why use brown sugar and not white? Brown sugar is just white sugar with a little bit of molasses added back. And how is a dilution of 1 ml per liter of water (1:1000) to 2.5 ml per liter of water (1:400) supposed to do anything for plants? Don’t forget your fermented juice is also mostly water, sugar and a little alcohol. This idea is like homeopathy for plants; complete woo-woo. Still, I suppose it couldn’t hurt either so feel free to waste your own time on it.

  • Rodolfo says:

    Does fermentation increase the nutrient content of particular leaves? Whats the range? Thanks.

  • Jean says:

    What is LAB?


After many years as a hobby, I began my career in Hydroponics working for Aquaculture in Sheffield, the UK's largest and most forward-thinking grow shops of the time. From there I began to work for Hydromag, responsible for the hydroponic content. Most notably, the product tests and comparisons, breaking ground in the industry and cutting through marketing hyperbole by showing consumers exactly how products stacked up against each other. From there I worked with CANNA, as editor of CANNAtalk, author of the research articles and delivering seminars throughout the UK to grow shops on the finer details of cultivating in a hydroponic environment. I'm currently writing for a number of companies in the hydroponic industry, of course, the most important of all being the powerhouse publication that is, Garden Culture.