The Ocean Has Every Mineral Your Plants Need
The Hilo KNF Monthly Meeting is a free, community-driven gathering held on the second Tuesday of every month at the Komohana Research and Extension Center. Each session focuses on one of Master Cho's nine core solutions of Korean Natural Farming, with hands-on demonstrations, tastings, and potluck dinner.
June's meeting — the seventh in the series — covered Minerals, the KNF solution most people overlook because the recipe is almost insultingly simple: get seawater, dilute it. Drake walked through the full mineral profile hiding in a bucket of Hilo Bay water (spoiler: all 108 elements, including gold), demonstrated how to reconstitute diluted seawater from sea salt when you can't make it to the beach, and ran through the application rates for every growth stage. Mike Dupont — who wrote the 2013 CTAHR paper on KNF solutions and was sitting in the back — got a well-deserved shoutout. The second half of the evening shifted to beetles: a recap of last month's sulfur and Metarhizium work from Daniel, a look at the Queensland longhorn beetle nematode program coming out of the Big Island Invasive Species Committee, Drake's own experiment with beetle-infused rice packed into a lauhala basket to culture insect-dissolving microbes, and Master Cho's bark repair spray — paint the moss, don't scrape it, and let the tree heal itself.
TL;DR: Minerals = seawater diluted 1:30 (one gallon ocean water to 30 gallons fresh water). If you can't get to the beach, reconstitute with sea salt: 30 grams per liter makes full-strength seawater; 1 gram per liter gives you the already-diluted 1:30 working solution. Use plain sea salt — not iodized. Dilution shifts by growth stage: 1:20 for soil drench and harvest, 1:25 for seed and fruit, 1:30 for bloom. Skip it during the leaf/vegetative stage. Spray the underside of the leaves — 25 gallons per acre foliar, 100–1,000 gallons per acre if drenching soil. One application at proper dilution delivers every mineral on the periodic table in water-soluble form the plant can use immediately. For bland fruit: ramp up seawater every five days in the final two weeks before harvest, going as concentrated as 1:10 the day before you pick.
Everything Is in There
Drake opened with a challenge: name a nutrient deficiency. Any deficiency. Boron — cell wall component — missing? Go to the ocean. Magnesium, the heart of every chlorophyll molecule? Go to the ocean. Iron locked up in Hāmākua red soil? It's out there in abundance, but it's bound up in mineral compounds the plant can't touch. Seawater iron is already water-soluble. It goes straight through the leaf, straight into the vascular system.
Mike Dupont's 2013 CTAHR paper — which was being passed around the room — lists the main players: nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, copper, manganese, zinc, boron, molybdenum, chlorine. But Drake waved at the rest of the periodic table. "Literally every single element. All 108 of them are in there. There's even gold in there." The practical consequence: you don't need to diagnose what's missing. You don't need to buy individual supplements and guess at ratios. You go to the ocean, you dilute, and you hit the whole board. The plant takes what it needs.
Seawater also brings something no synthetic mineral product can match: a completely different branch of the microbial family tree. Saltwater microbes colonize your soil and start interbreeding with whatever is already there. Microbial diversity climbs. Old, tired land gets a transfusion. Drake's analogy: "You're on the island, it's like, ah, you've seen everybody already. But the seawater comes off and it's like — oh. Three arms."
Seawater also breaks up compacted soil physically. Dense soil sits in platelets stacked like plates. Adding diluted seawater is like wedging ping-pong balls and tennis balls between those plates — the structure buckles, air can flow through, water can move again. That's a straight chemical reaction, not biology.
Gathering: Where and How
Where you gather matters. Drake had a gallon jar on the table he'd scooped from Hilo Bay on the way over — rocks and all, because he wasn't going to take his shoes off to wade past the crowd at the shoreline. Hilo-side water is diluted somewhat by freshwater runoff from Mauna Kea. Freshwater is lighter and sits on top; seawater is denser and sits below. If you go to a tide pool, you can lower a hose and pull specifically from the saltwater layer underneath. Or just wade into the surf zone, where everything is mixed and the mineral concentration runs high.
Drake's friend Lloyd goes further offshore in his boat and drops a straw twenty feet down to pull from older, quieter water below the surface churn. The concern that prompted the question: contamination. Fukushima is still leaking. Hilo Bay has its own issues. "Try to gather from a spot where you think it's nice and clean." At proper dilution Drake doesn't think there's a realistic overdose risk — the mineral balance you end up with is close to the mineral balance in blood — but knowing your source is still worth doing.
For farmers up in the hills who can't make regular beach runs: in Kona, at Nauha near the airport, there's a tap where you can pull from 2,000 feet below the surface. Drive over with a 275-gallon tote and they'll fill it. That depth keeps the water cold and old, below surface contamination layers. Alternatively: reconstitute from salt at home.
Two Ways to Make It: Ocean or Salt
Fresh seawater is free and comes complete. When you can't make it to the water, sea salt gets you most of the way there.
From seawater: fill your container, dilute 1:30. One gallon of ocean water to 30 gallons of fresh water. That's the whole recipe.
From sea salt: 30 grams per liter of fresh water gives you full-strength seawater. To make the already-diluted 1:30 working solution directly, use 1 gram per liter. Drake weighed out 30 grams on the scale — it's a small handful, about what fills a jar lid — to show how much salt is actually dissolved in one gallon of seawater. He uses Celtic sea salt because that's what Costco has been carrying, but any plain sea salt works. A 5-pound bag runs around $20 and goes a long way across a farm.
Do not use iodized salt. You won't get the mineral profile you're after, and the additives aren't the point. This specifically requires sea salt — the mineral complexity is the whole reason you're doing it.
Seawater salinity varies around the world, roughly 3–7%. Diluting at 1:30 puts you in a safe range regardless of your source. If your land is badly exhausted — Hāmākua red soil where the topsoil was bulldozed years ago — go a bit stronger. For delicate seedlings, go lighter. Watch the plant and adjust.
Application Rates by Growth Stage
Minerals appear in nearly every KNF formula. The dilution shifts depending on what the plant is doing:
- Soil solution (remineralizing ground): 1:20 — slightly stronger because it's going straight into the soil
- Seed solution: 1:25
- Bloom phase: 1:30
- Fruiting phase: 1:25
- Harvest (last 2 weeks): 1:20, ramping to 1:10 the day before you pick
- Leaf/vegetative growth phase: not in the formula
Why skip the leaf stage? "In that growth stage, it's like chubby growth — growing solar panels. Adding the minerals aren't as important. It's more trying to grow fast than harden." Minerals firm things up. The leaf stage is soft and expansive on purpose, and you don't want to push the plant toward hardness when it's trying to build canopy.
Application method: foliar spray on the underside of leaves is most efficient — stomata concentrate there, and the plant absorbs directly through its body. Foliar rate is 25 gallons per acre. Soil drench is 100 gallons per acre minimum; 1,000 gallons per acre if you want to actually wet the top inch of soil thoroughly. When running irrigation, use reconstituted salt rather than raw seawater — raw seawater carries biology that will colonize and clog lines if it sits.
Bland Fruit, Sweet Coconuts, and Hungry Cows
The sweetness connection is one of the most compelling practical arguments for minerals. Papayas from Puna — grown on flat fresh lava, saturated with volcanic mineral release — are legendarily sweet. Same variety grown on the Hilo side: often mediocre. Same plant. The difference is minerals. Throw seawater on the Hilo-side papayas and you'll close that gap.
The harvest-ramp technique: for the last two weeks before picking, apply minerals every five days and increase the concentration each time, finishing at 1:10 the day before harvest. The slightly elevated salt stress in those final days pushes the plant to concentrate sugars and flavor compounds. Not enough to damage it — just enough to trigger the response. Combined with Structure (water-soluble calcium phosphate, which we covered in April), this is the formula for consistently sweet, dense fruit.
Coconuts are the most dramatic example. The sweetest coconuts come from trees near the beach, roots practically in the tide. Drake asked the room where the best coconut water comes from. "Mauka? Tastes like someone rinsed out the socks." The beach trees are drawing straight seawater. That's the whole story. Coconuts can tolerate full-strength, undiluted seawater poured around the root zone — they're one of the few plants that can. If you have a coconut in Hawaiian Acres that's getting small and scrawny (almost always a mineral problem), Drake's prescription: haul 20 gallons of Hilo Bay water up and dump it straight around the roots. A couple of teaspoons of salt per bucket isn't enough. Coconuts want the real thing.
The same principle holds for livestock. Drake keeps a bucket of straight Hilo Bay seawater alongside a freshwater drinker for his cows. They self-regulate — they go to the seawater first, drink what they need, then switch to the fresh. The best-finished grass-fed beef in Hawaiʻi comes from cattle grazing near the coast, where sea minerals blow inland and concentrate in the grass. Bring the seawater to your mauka pasture and you replicate that effect.
Beetle Dispatch: Nematodes, Sulfur, and Drake's IMO Experiment
The second half of the evening shifted to beetles. Drake framed it simply: "It's the end times. The beetles are coming for us. My motto: end the end times."
Coconut Rhinoceros Beetle: A brief recap of Daniel's visit last month — JADAM water-soluble sulfur sprayed into the coconut canopy to mask the scent signature the CRB uses to navigate, and Metarhizium anisopliae inoculated into mulch piles to attack grubs where they spend 80% of their life cycle. Daniel reported an 80-plus percent reduction in grub counts at his trial site after a single application. (Full details are in last month's recap at pureknf.org.)
Queensland Longhorn Beetle: Drake caught one on his porch screen earlier in the week — it came to the light at night — and held it up in a jar. Three days in a jar and it dies on its own. He attended a workshop at Ulukua shortly after catching it and brought back the current management approach: nematodes. The Big Island Invasive Species Committee is culturing a specific nematode on mealworms, liquefying the resulting solution, and distributing it for free. To apply it, you find where the beetle has bored into a tree — look for sawdust oozing from an entry hole — and inject the nematode solution in with a needle. The nematodes eat the larva inside, then stay resident in the tree and prevent reinfection. It works, but it's tedious: you have to locate every entry point, get the needle in, and deliver enough of a population for it to take hold. It's not a broadcast spray. And it only works on larvae — once the beetle has hatched and left the tree, that particular individual is beyond reach.
Drake's IMO Collection Experiment: This one was live, speculative, and Drake was upfront about that. He picked up a bag of dehydrated beetle and mealworm corpses at Tractor Supply — sold as a protein supplement for chickens — and cooked them into rice: two jars of rice, one jar of bug meal, about 80% of a jar of water, done in the instant pot until slightly dry. The cooked, cooled mixture goes into a lauhala basket or a woven container.
The basket then gets set in the forest floor — under a mango, under ulu, somewhere with a healthy native microbiome — and buried so the bottom is in direct soil contact. Cover the top with the removed soil, pile leaves around it, set a metal cage over the top to keep rodents out (metal on top only, not underneath — the soil contact is essential), add a small roof for weather. Come back in a week and the basket will be colonized: mycelium, bacteria, fungi, nematodes, protozoa — the local microbiome concentrated into a dense inoculum. By loading the rice with beetle bodies, Drake is selectively attracting the organisms already adapted to dissolving chitin and digesting insect material.
The theory: propagate that beetle-hostile microbiome at scale, bulk it up through repeated substrate inoculation, and spray it across the whole farm. "If I can get it all out on my land where the bug has no quarter — it lands and everywhere it goes it's just like itchy and irritating — the bug may even just leave." Drake also wants to try introducing the BISC nematode culture directly into a collection basket to see if that specific nematode will propagate in the IMO system — which would make it possible to produce enormous quantities without the painstaking mealworm-culturing process. Not proven against Queensland longhorn or CRB yet, but the underlying mechanism of tuning a microbial community toward a specific pest target has precedent. Science in action.
Master Cho's Bark Repair Spray
The final segment came from a Master Cho video Drake had gone back through earlier in the week — filmed at Jackie and John's farm, the same photo Drake had shown at the start of the meeting. Cho's subject: trees with moss on the bark.
Moss on the trunk is a symptom, not the problem itself. It signals sunburn — bark that has lost circulation, gone dormant, and started weeping sap at the surface. Beetles, including the Queensland longhorn, preferentially attack trees already in this state. The ulu tree in the orchard that had been hit had moss on it. The beetles aren't always going after healthy trees at random. They're responding to a tree that is already broadcasting distress.
Don't scrape the moss. Don't power-wash it. Removing the moss is like pulling the scab off a sunburn too early — you're destroying the protection while the tree is still healing underneath. Leave it. Treat the deficiency underneath it.
Master Cho's spray formula for mossy bark: Medicine (OHN) + Cleanser (BRV) + Liquid IMO + Minerals (ocean water). Apply weakly and consistently — weekly until the moss falls away on its own. It will, once circulation is restored and the bark underneath firms back up. The medicine treats, the cleanser cleans, the IMO is a living skin graft, the minerals rebuild. Tony's kaolin clay mix was mentioned as an excellent vehicle for this — the clay helps everything adhere to the bark surface and holds moisture in contact with the wood.
For trees that have been girdled — bark actually stripped by beetle boring activity — the formula gets painted on rather than sprayed, and sweet rice starch (or oatmeal) gets added to make it stick to bare wood. Drake has seen completely debarked trees painted with this formula slowly scab over, close the wound, and come back. The starch holds everything in contact while the biology does its work. Repeat weekly. When the bark starts to visibly close, the leaves will come back, because the circulation problem that was dropping them is being addressed.
The through-line connecting everything tonight: healthy, mineralized trees with active circulation don't sunburn, don't moss, and don't attract beetles. The minerals, the IMO, the medicine, the cleanser — used together and applied consistently — are the defense system. The beetle is the consequence of skipping the maintenance, not a random attack from outside. "If you don't want the beetle, take care of it ahead of time."
The Hilo KNF monthly meetings are held at the Komohana Research and Extension Center, 875 Komohana St, Hilo. All are welcome — bring a dish to share.
Next Month: July 14, 2026 — Reproduction (Bloom & Fruit Support)