Korean Natural Farming: The Inputs Behind the Method

Korean Natural Farming (KNF) is a system of growing developed by Cho Han Kyu in South Korea that relies on fermented and cultured biological inputs made from locally available materials. It is not a single product or a brand. It is a framework: a set of inputs, each with a distinct role, applied in sequence with the plant's growth cycle.

The inputs are made at home from common materials, or purchased pre-made from producers who follow the same formulations. What makes the system work is not any individual input but how they function together as a biological program.

The six core KNF inputs

FPJ — Fermented Plant Juice

FPJ is made from young, actively growing vegetative plant material: new shoots, growing tips and fresh leaves at the moment of maximum vitality. These tissues are high in plant hormones, growth-promoting compounds and the nutrients the plant is using to build itself. Packed with brown sugar and left to ferment via osmotic extraction, FPJ captures those compounds in concentrated liquid form.

FPJ is the vegetative-stage input. It supports growth, vigor and the development of healthy vegetative structure. Most KNF practitioners use it from seedling through mid-veg, tapering off as the plant approaches the transition to flower.

FFJ — Fermented Fruit Juice

FFJ is made from overripe fruit using the same osmotic extraction method as FPJ. Fruit at peak ripeness is high in simple sugars, organic acids, enzymes, and the compounds associated with the plant's reproductive stage. The fermentation converts these into a bioavailable concentrate.

FFJ is the flowering-stage input. It feeds soil biology, delivers free amino acids for enzymatic demand, activates the SAR pathway through salicylic acid (when aloe is included), and provides cytokinins that support cell division in developing flower tissues (when coconut water is included). It picks up where FPJ leaves off and runs through the flowering cycle. For a complete explanation of how FFJ works, see our FFJ guide.

OHN — Oriental Herbal Nutrient

OHN is a fermented extract of aromatic herbs and roots: traditionally garlic, ginger, cinnamon bark, licorice root and angelica root, though formulations vary. The aromatic compounds concentrated through fermentation give OHN broad-spectrum antimicrobial and antifungal properties.

OHN is applied as a preventive pest and pathogen deterrent, typically as a dilute foliar spray or soil drench. It is not a pesticide in the conventional sense — it is a plant tonic that creates an environment less hospitable to pathogens. Some practitioners also attribute secondary metabolite support to OHN, as the aromatic compounds may function similarly to mild SAR activators, though the mechanism is less well-documented than the aloe/salicylic acid pathway.

WCA — Water-Soluble Calcium

WCA is made by dissolving eggshells or bone in food-grade vinegar. The acetic acid reacts with calcium carbonate to form calcium acetate, a water-soluble, immediately bioavailable form of calcium. Left to fully dissolve and diluted appropriately, it delivers calcium without the pH disruption of lime or calcium carbonate amendments.

Calcium is critical throughout the growth cycle but especially during flower development. It is essential for cell wall strength, the structural integrity of flower tissue and the translocation of other nutrients. WCA applied during flower supports calyx hardening and overall flower density. It is typically applied as a soil drench at 1:1000.

LAB — Lactic Acid Bacteria Serum

LAB serum is captured from the environment and cultured in whole milk. Traditionally, rice wash water is left out to collect wild Lactobacillus bacteria, then added to milk. The Lactobacillus out-competes the other bacteria in the milk, producing lactic acid and causing the protein to separate. The liquid whey that separates out is the LAB serum, rich in Lactobacillus populations and their metabolic byproducts.

Applied to soil or as a foliar, LAB serum introduces beneficial bacteria that acidify the rhizosphere slightly, improve mineral availability, compete with pathogens and contribute to the breakdown of organic matter. FFJ naturally contains LAB from the fermentation process, so growers using FFJ are already getting LAB with each application.

FAA — Fish Amino Acid

FAA is made by fermenting whole fish or fish scraps with brown sugar, producing a nitrogen-rich fermented liquid high in free amino acids. It is the most potent nitrogen source in the KNF system — a strong organic nitrogen supplement that supports vegetative growth and can be used in flower at reduced rates when the plant shows nitrogen demand.

FAA smells exactly as you would expect. It is applied at high dilution (1:1000 or greater) as a soil drench.

How the inputs fit together

The KNF system is not applied all at once. Each input has a primary stage: FPJ in veg, FFJ in flower, OHN as a periodic preventive throughout, WCA throughout and especially in flower, LAB as a soil builder whenever needed, FAA as a nitrogen supplement when the plant signals demand.

For a stage-by-stage schedule, see our KNF input timing guide.

Our pre-made FFJ is built on the KNF fermented fruit juice formulation, CDFA registered and ready to dilute. Browse formulas.