The Humic & Fulvic Range

Ancient carbon for modern soil

Humic and fulvic acids are the dark carbon fractions of humus, formed over millions of years from plant material in ancient peat and Leonardite deposits. They are among the most heavily researched soil amendments available to gardeners, and they do two different jobs. Humic acid works in the soil. Fulvic acid works inside the plant.

Fulvic acid vs humic acid

It is the question we are asked most often, and the honest answer is that they are not competitors. The difference comes down to molecular size, and everything else follows from it.

• Size. Humic molecules are large and largely stay where you put them, binding to clay and organic matter and building a reservoir in the root zone. Fulvic molecules are much smaller and stay soluble at any pH, small enough to cross a root cell wall or a leaf cuticle.
• Chelation. Both chelate: they wrap around mineral ions and hold them in a form a plant can use. Humic chelation mostly keeps minerals available in the soil, where they would otherwise lock up or leach. Fulvic chelation carries them into the plant.
• Where each acts. Humic acid acts on the soil, on structure, cation exchange capacity, water holding and microbial food. Fulvic acid acts inside the plant, on uptake and transport, with a foliar response measured in hours rather than seasons.
• When each is useful. Humic once or twice a year as groundwork, ideally autumn or at planting. Fulvic through active growth, when you want the nutrition you are already applying to be used more efficiently.

If you only take one thing from the comparison: fulvic gives faster visible results, humic gives the deeper long-term soil benefit, and neither is a fertiliser. They make nutrition work harder; they do not supply much of it themselves.

Two molecules, two jobs

• Humic acid is the larger, alkali-soluble fraction. It stays in the soil, raising cation-exchange capacity, holding water and nutrients in the root zone, opening compacted clay and feeding the soil microbes. A long-term investment in structure. Full background in what humic acid is and what it does, with the benefits of humic acid for plants set out separately.
• Fulvic acid is the smaller fraction, soluble at any pH. Its molecules chelate minerals and carry them through cell walls, which improves uptake of whatever nutrition is already there. Applied as a foliar spray or root drench. See what fulvic acid is and the eight benefits with the evidence behind each.

If you are choosing between them, the one-sentence difference and which you actually need is the guide to read.

What is in the collection

• Fulvic Acid Powder, 70% fulvic and 99% soluble. Dissolves clean for foliar and drench use.
• Humic Acid Flakes, 70% humic and fully water soluble. Leonardite-derived, for soil application and fertigation.
• Slow Release Humic Acid, granular Leonardite humate. For a single autumn or spring application that keeps working.
• Boron Humate Granules, 3.23% boron complexed with humic acid. Boron in a form that resists leaching, which matters because boron has a narrow window between deficient and toxic.

Humates and Leonardite: where this material comes from

Humates is the collective term for the salts and complexes of humic substances, which is why you will see potassium humate and boron humate on labels alongside plain humic acid. A humate is simply humic acid bound to something else, usually to make it more soluble or to carry a nutrient with it.

Nearly all of it starts as Leonardite, a soft brown coal formed from ancient plant material and the richest natural source of humic substances known. It is the standard feedstock worldwide, and the reason a granular humate and a soluble flake can come from the same seam. Quality varies more than the category suggests: humic percentage, solubility and ash content differ substantially between deposits, so the figures on a label are worth reading rather than assuming.

Fulvic acid supplements: these are garden inputs

A plain note, because the search term brings people to this page. Fulvic acid supplements sold for human use are a different product category with a different purpose, and nothing in this collection is one. Everything here is a garden input for outdoor soil and plants, applied to the ground or sprayed on leaves. It is not food, and we make no health claim of any kind. If you are looking for a supplement, this is not the right page.

How to use them

Apply humic flakes to the soil at planting or as a top-dress, then water in; how to apply humic acid covers the method in full. Apply fulvic powder as a foliar spray at 0.5 to 3 g per litre, or as a root drench, every one to two weeks through active growth, and there is a liquid fulvic acid if you would rather not mix a powder. Rates matter more with fulvic than with most inputs because it shows a hormesis response: past a certain point, more is not better. The rates and method, with the peer-reviewed dose data.

Both pair cleanly with the main fertiliser range and with biostimulants. On light ground, humic acid works well alongside soil conditioners, since both are doing the same job of giving a soil something to hold nutrients with.

Common questions

Do I need both?

Ideally yes, because they act in different places. If you can only buy one: fulvic gives faster visible results, humic gives the deeper long-term soil benefit, and a humic and fulvic blend carries both in one bag.

Can I take these as a supplement?

No. These are garden inputs for soil and plants, not for human consumption.

Are humates the same thing as humic acid?

Close, but not identical. Humic acid is the acid itself; humates are its salts and complexes, such as potassium humate. In garden use the practical difference is solubility and what else is carried along with it.

Can I mix them with my fertiliser?

Yes. Both improve how efficiently the plant takes up whatever you are already feeding, whether that is a granular blend or a liquid feed, so they make an existing programme work harder rather than replacing part of it.

Will humic acid change my soil pH?

Not to any degree you would measure at garden rates. It is a carbon and cation-exchange amendment, not a liming or acidifying material, so use sulphur or calcium carbonate if pH is what you are trying to shift.

Are they safe for seedlings?

Yes, at reduced rates. Use half the standard dilution for the first two to three weeks.

What is the shelf life?

Indefinite when stored cool, dry and sealed. Both are stable solids.

Where does the humic acid come from?

Leonardite, a soft brown coal formed from ancient plant material. It is the richest natural source of humic substances available, which is why it is the standard feedstock worldwide.

How long does humic acid take to work?

Water holding and nutrient retention improve over weeks. Structure takes a season or more. Fulvic is the one to reach for if you want to see something happen quickly.

What does cation-exchange capacity mean in practice?

It is a measure of how much nutrient your soil can hold onto rather than lose to drainage. Sandy soils have low CEC, which is why feeding them can feel like pouring water through a sieve. Humic acid raises it, and so does montmorillonite clay.