Is Azomite Good for Orchids?

When fertilizing your orchids with a balanced fertilizer such as 20-20-20, you’ll soon find out that you also need to add fertilizer supplement. Supplements provide your orchid with the remaining micronutrients that are not provided in your regular fertilizer. By adding fertilizer supplements to your orchid potting media, you’ll enhance its growth.

Azomite is a product that often comes up as a possible candidate for fertilizer supplement. In this article, I’ll detail what is in Azomite, if you should use it, and what orchids are best aided by using Azomite.

In essence, Azomite is not beneficial in your orchid care.

You will need to activate Azomite before you add it to your potting medium with the use of specific microbes found in the soil. Without these specific microbes that can break down this low soluble mineral into elements that the orchid can absorb, Azomite will not affect your orchids.

Even when you activate it by breaking it down into elements that the orchid can consume, the time required to make Azomite soluble would be shorter than the time required to repot.

I arrived at this answer by asking a few questions:


1) what orchid do you have (epiphytic or terrestrial), 
2) do you have a way to provide more beneficial microbes to the orchid so they can break down Azomite into soluble minerals,
3) how long do you have before you repot? Let’s look at those one by one.

What is Azomite?

Azomite is a registered brand name, not the product itself. Other brand names of the similar volcanic dust are Elemite and Excelerite. You can see Azomite’s website here. (Link)

This volcanic ash, similar to rock dust, belongs to the hydrated sodium calcium aluminosilicate (HSCAS) group. Azomite is made of million-year-old volcanic dust (similar but smaller than pumice) that has been hardened into a rock formation. It is sold as a soil amendment product and an agricultural fertilizer, to replenish the minerals that your soil has lost over many years of leeching (either rains or bad weather).

Volcanic dust of over 30 million years ago landed on the oceans and slowly drifted down to the seabed. Once those seas dried up, a combination of dried plants, seaweeds, volcanic dust, and fossilized animals formed a hard layer of rock. This unique mixture of elements is rich in minerals and natural chemicals.

Since Azomite is the most common seller of this product, the brand name is what it generally is referred to instead of the factual name, rhyolitic tuff breccia.

The idea behind the name is that this rock formation is that it contains all the trace elements from A to Z. Their slogan includes the phrase, “A to Z of Minerals Including Trace Elements”. Azomite is mined in Utah, USA, and from there it is shipped to the rest of the world.

What are the elements in Azomite?

The idea behind using a product like rock dust, volcanic dust, or other forms of minerals is to remineralize the soil. Water will leech the minerals out of the pot over years, leaving a weak soil. Weak soils lead to weak plants.

To use methods like Azomite, is to place minerals back into the soil, making the soil nutrient rich again.

Being slightly alkaline, Azomite, in theory would be good for orchids because it does not raise the pH of the potting media and still allows good water circulation to exit the pot. (Source)

Since Azomite provides a high source of Calcium and Magnesium, it could be an excellent way to use as a supplement along with your normal orchid fertilizer—in theory. Even if I agreed to using Azomite for orchid care, it isn’t suited for orchids if used as your only source of fertilizer.

Orchids need macronutrients known as the NPK ratio, which is nitrogen, phosphorous, and potassium. These come in all well-known fertilizer for orchids.
Yet orchids don’t live on only those three chemical elements, and need a lot more, namely, the micronutrients. I wrote a whole article on the NPK ratio and how to understand it, which you can read here.

The most important nutrients outside of NPK are calcium, magnesium, manganese, iron, boron, and sulfur.

As a fertilizer, the NPK of Azomite is 0-0-0.02. This translates as it contains no nitrogen, no phosphorus and a tiny bit of potassium. Yet it isn’t intended to be a complete orchid fertilizer, but to be an orchid supplement. As a supplement, it contains more than 70 trace elements, such as 5% potassium, 3% calcium, 1% magnesium, and 1% iron. (Source)

Any rock dust (volcanic or not) is known to sequestrate carbon dioxide and fix in into the soil. This will raise the % of carbon dioxide in the soil, which has exceeding benefits in the long run.This is why most people jump to the conclusion that Azomite works well with orchids. It would be, if orchids could consume it in it’s natural form.

For some reason, it’s extremely hard to find a complete list of the exact percentages in Azomite. Impossible is a better word.

In some places that I’ve read, the authors were very leery of using rock dust, saying it is a scam. The reason that there are no lists of the exact elements in the Azomite (or other rock dusts) is that there aren’t many to start with. You might be getting 1% Calcium, but the rest is what has adhered to the calcium deposits and are insignificant when placed on a percentage scale. Surprisingly, it wasn’t only one person who shared this view about rock dust.

How does Azomite influence orchid growth?

Azomite will create sturdy cells, increasing disease resistance, and make the orchid stem firm. It does this by replenishing the nutrients that may have been leeched away from the soil.

If your soil is a good, rich soil which contains all the natural percentages of what your terrestrial orchid needs, then you will gain nothing from adding Azomite. Your soil already has the nutrients it needs to produce the same effects that Azomite will.

If your soil is nutrient deficient, then the beneficial effects of Azomite are visible in 2-3 weeks (This author of this claim was referring to a crop planation, not an orchid pot).

Traditionally used as a crop fertilizer, Azomite was used by farmers to get bigger, healthier fruits. Customer reports say that the produce was healthier and had more quantity than earlier crops without the product. No studies were done with orchids.

As for orchid care in my home office, I’m not focusing on seed production or germination of seed pods. That is not something I am into since for most orchids, you would need a lab and highly sterilized equipment along with special fungus to create a mycorrhizal relationship with the seeds.

I’d prefer to buy my orchids online. If you need tips on how to buy orchids online, this article I wrote is a good suggestion (in my most humble opinion).

But let’s say that you just want a healthier plant and even though you aren’t into producing seeds, you are looking forward to having a healthier plant. In this case, let’s look at how Azomite works.

How does Azomite work?

If Azomite is essentially just a rock, how does the orchid absorb any of its nutrients? Azomite by itself is an insoluble mineral (maybe not totally insoluble, but very hard to break down). If no other mechanism is present that will break down this mineral, then it will just sit there, just as it has done for the last 30 million years.

None of the volcanic ash or rock dust companies have a statement on their websites stating how long their product takes to break down—not one. In one article I read citing, the author stated that rock duct takes over 100 years to break down. No proof was given.

Yet, I must repot my terrestrial orchids every 4 years.

Microbes are essential in breaking down rock dust or volcanic dust.Which comes to the most important part of this article: there aren’t many microbes that are present in the orchid pot.

Orchids are an extremely vast group of plants but in the most part, they are epiphytes (grow on trees) and not terrestrial. Here’s the catch: the microbes that inhabit the soil are not the same ones that we will find in our orchid potting media created to imitate tree trunks.

Even if I add Azomite to orchid bark and sphagnum moss, which are the main potting medium of Phalaenopsis orchids, the beneficial bacteria that will grow in this habitat will not be the same microbes that will consume Azomite. To consume and break down Azomite into a soluble form that is any use to orchids, then terrestrial bacteria are needed.

In the study “Bacteria associated with orchid roots and microbial production of auxin” that was published in microbiological research, the authors proved that different microbes will concentrate around aerial roots than terrestrial roots. (Source)

The above news is not all bad news, since not all orchids are tree-huggers. The bacteria that Azomite needs will be plentiful in soil, so if you have terrestrial or semi-terrestrial orchids, then Azomite might work (in theory).

The little addition, in theory, is because of time. How long will microbes take to break down the volcanic dust into minerals that can be used by plants? I found no real answer here… In one article the answer was a suggested 100 years. No proof was shown—no data, no graphs, no experiments, no geo-expert’s quotes…

Nothing. The company claims 2-3 weeks, yet no studies have proven that.

If you are repotting in 3 to 4 years, then essentially, you are throwing out all the soil and replacing it with new soil. The Azomite that you added along with some form of extra microbes that are favorable to its breakdown will be replaced with new soil that already contains all the minerals that your orchid needs.

Examples of Terrestrial Orchids

  • Acanthephippium
  • Bletilla striata
  • Cynorkis
  • Cyripedium
  • Dactylorihza
  • Erythodes
  • Eulophia
  • Hetaria
  • Liparis
  • Macodes
  • Nervilia
  • Pachystoma
  • Phaius
  • Pterostylis
  • Spathoglottis plicata
  • Spiranthes
  • Zeuxine

Without microbes that can break down this low-soluble mineral into elements that the orchid can absorb, Azomite will not affect your orchids. You will need to activate rock dust to make it of any use to your orchid before you add it to your potting medium. Even when you activate it, the time to make Azomite soluble would be shorter than the time required to repot.

How to Make Azomite Work in Your Orchid Media

To activate Azomite, or any other rock dust or volcanic dust, you need to follow a few steps. These will come naturally in time so starting the first one will automatically increase the others.

First, you need to use bioflavonoids, or just flavonoids on the top of your media. This is inducing the orchid roots to produce sugar, called root exudates, attracting more microbes and stimulating their health. With more beneficial microbes in your potting media, they will consume the rock dust. (Source)

I have found that the evidence stops here… There is nothing more about how long this takes. If a company would conduct some studies and prove that it is 2 – 3 weeks, then I might change my mind. My hypothesis is that this is not something that would happen quick. Millions of years have passed and the rocks are still rocks. Even if were quick, I’d still have to find a way to influence more microbes to come live inside the orchid pot.

“CON”clusion for azomite and orchids

By itself, Azomite will not aid your epiphytic orchids because it is insoluble. That’s why it’s been around for 100’s of millions of years. Terrestrial or semi terrestrial orchids will react better to Azomite because they have microbes in the soil that transform Azomite into elements that your orchids can absorb and consume, but the time to conclude this transformation is well beyond repotting time.

Even if you have a way of breaking down this mineral, the process is longer than the time you need to repot. Considering these arguments, Azomite is a not great addition to your orchid potting medium and should be avoided.

Don’t Stop Learning!

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Orchid Fertilization

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In all, I wish you the best in your orchid care. Happy cultivating!

Signature Amanda Matthews


Amanda Matthews

Amanda Matthews is a theological professor, author, pastor, and a motivational speaker. She's passionate about spreading hope and teaching. Her hobbies include biking, cultivating orchids, and exploring nature trails. She now lives in Kansas, while raising her two children. To read more, go to https://orchideria.com/about-the-author

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