How to Make Oriental Herbal Nutrient (OHN) for Korean Natural Farming

OHN is an extraction, not a fermentation. You are pulling the antimicrobial and plant-stimulating compounds from aromatic herbs into a liquid medium using either sugar or alcohol. The process takes 5-7 days and produces a concentrated extract that is used at very high dilution throughout the growth cycle.

For context on what OHN is and how it fits the KNF system, see our OHN overview.

The core herbs

Three herbs are consistent across traditional OHN recipes:

Garlic. The highest-priority ingredient. Garlic is rich in alliin, which converts to allicin when the cell walls are broken — this is where garlic's documented antimicrobial activity comes from. Fresh, intact bulbs are far better than pre-processed garlic.

Ginger. Contributes gingerols and shogaols, both with antimicrobial and anti-inflammatory activity. Fresh ginger root, not dried powder.

Cinnamon bark. Cinnamaldehyde, the primary active compound, is a broad-spectrum antimicrobial that disrupts bacterial cell membranes and inhibits fungal growth. Use whole sticks or chips — ground cinnamon loses volatile compounds quickly and is harder to strain.

Optional additions used in some traditions: licorice root (glycyrrhizin, adaptogenic compounds), angelica root, green onion. These are supplemental, not critical. A three-herb batch of garlic, ginger and cinnamon produces quality OHN.

Method 1: Brown sugar extraction (traditional KNF)

This uses osmotic pressure to extract compounds from the herbs, the same mechanism used in FFJ and FPJ production.

Materials:

• 1 part garlic (roughly chopped or lightly crushed, not minced)
• 1 part fresh ginger (roughly chopped)
• 0.5-1 part cinnamon bark chips
• Brown sugar: equal to the total herb weight

Process:

1. Weigh your herbs. Chop garlic coarsely — the goal is to break cell walls to release allicin without creating so much surface area that straining becomes difficult.
2. Layer herbs and sugar in a glass jar: herbs, sugar, herbs, sugar, ending with a sugar cap on top.
3. Cover loosely with cloth. Do not seal — fermentation activity produces CO2 and the cloth allows air exchange.
4. Leave at room temperature (65-80°F) for 5-7 days. Stir daily.
5. Liquid will accumulate as the sugar draws compounds out of the herbs. By day 3-4, there should be significant brown liquid in the jar.
6. Strain through cheesecloth or fine mesh. Squeeze the herb solids to extract remaining liquid.
7. The finished OHN should be dark amber to brown, strongly aromatic (garlic, ginger, cinnamon are all clearly identifiable), and sweet-acidic.

Shelf life: 6-12 months in a sealed container. Refrigeration extends stability.

Method 2: Alcohol extraction

Alcohol extracts compounds more efficiently and produces a more stable, longer-lasting product. This is preferred by growers who want a consistent, potent extract that stores well.

Materials:

• Same herbs as above
• Rice wine, soju or any grain-based alcohol at 25-35% alcohol content (do not use rubbing alcohol — food-grade only)

Process:

1. Roughly chop the herbs and place in a glass jar.
2. Pour the alcohol over the herbs until they are fully submerged.
3. Seal the jar. Leave in a cool, dark location for 5-7 days. Shake daily.
4. Strain and store. The alcohol-extracted OHN has a sharper, more concentrated aromatic profile than the sugar-extracted version and keeps longer.

Some practitioners do a two-stage extraction: sugar first for 3-4 days, then drain off the liquid, add alcohol to the same herbs and extract for another 3-4 days, then combine the two extracts. This pulls both water-soluble and alcohol-soluble compounds.

What finished OHN should look like

Color: amber to dark brown. Alcohol-extracted OHN is typically lighter than sugar-extracted.

Smell: intensely aromatic — garlic, ginger and cinnamon should all be clearly identifiable. The smell is strong at full concentration and will carry across a room when opened. This is normal and expected.

Taste: pungent, sweet (from the sugar if using the sugar method), spicy from the ginger and cinnamon.

A batch that smells primarily of fermented vegetables or has a flat, musty smell rather than active herb aromatics may not have extracted well. Check that your herbs were fresh and aromatic before you started.

How to apply

Soil drench: 1 mL per liter of water (1:1000). Apply once every 10-14 days throughout the growth cycle. Do not increase frequency to more than once per week — OHN's antimicrobial action is not pathway-selective at higher concentrations, and you can inhibit beneficial rhizosphere organisms as well as pathogens.

Foliar: 1 mL per liter, applied to leaf surfaces. Spray during lights-off or in lower-humidity periods so the application dries before high-humidity windows. Stop foliar applications by week 5 of flower.

Use case: OHN is a preventative, not a curative. Applied consistently from early in the growth cycle, it maintains an environment unfavorable to pathogen establishment. If you are dealing with an active infection, OHN is not a treatment. Manage the infection with appropriate interventions first, then use OHN as part of a post-treatment prevention protocol.

If you are running our FFJ formulas, the core organic inputs for the flowering stage are already handled — [join the waitlist to be notified when we launch].