Is Azomite Rock Dust worth the investment?

$44 for 40lb bag of it on Amazon.  I hear some people say the microbes can access the minerals and provide them to the plant.  Another guy says they can't be accessed and it is a quarry yard waste product cleverly marketed and is a gimmick and not worth it.

I am ammending my soil now and getting my beds ready for spring.  I mixed the existing soil with Black Kow, Peat Moss and compost from my pile (from leaves, grass cuttings, twigs, starbucks coffee grounds, etc..).  I wouldn't of bought the Black Kow, but just started gardening last fall and my compost pile wasn't that big.   I'm going to make sure I build much larger compost piles this year for the following year -- the soil is amazing. Black Kow has like no smell to it, but my compost pile smells like my worm bin inside the house, that rich soil smell.  (I'm going to work in a pint or so of worm castings into each 4' x 4' raised bed as well -- I'd do more but I just started that in the fall as well and I wasn't feeding them nearly often enough.)

I got the Peat because that's what Mel B. said to use in Square foot gardening book.. but I skipped the vermiculite because of the expense.   I now know it isn't a renewable resource and took thousands of years to make.  I guess in the future I'll have to use something else but want to keep costs down.. coconut coir is insanely expensive.

The first question is - Does your soil need it? This is the sort of thing that you need to have a good soil test for - don't do it "because."  While I think it it is true that the soil chemistry doesn't need to be as perfect as suggested - especially in the presence of good microbial activity - severely depleted soil might need a kick of something like this.  I've added some in test strips to my pastures to see how much of a difference it makes.

If you do need it, don't buy it at Amazon!  My super-informed and reputable local supplier has 44 lbs for $19.

I would do sea90 over azomite. But yes if you are buying peat most and compost buy azomite too.

As Eliot said, it should be based on need.

In my location we have sedimentary chalk soils. Mineral depletion is definitely a thing around here, to the point that even thousands of years ago people were digging vertical shafts in the fields to mine for chalk that hadn't had all the minerals leached from it by rain water.

That said, by using lots of mulch and compost in our growing areas we have not noticed any significant issues with our plants.

I have 6 raised beds, all are similar composure.  I've only had one season (fall crop) with four of them.. added two new beds this spring.  Would it be good enough to sample just one of the beds or perhaps mix all 6 together and sample that?   I can't afford to sample all 6 raised beds as the local extension suggests.   They are only 4' x 4' beds.

Oh dear - I'd disagree with that suggestion.  They usually suggest combining samples from "similar" areas - thus I collect and mix together a sample from the orchard, another sample from the top field and yet another from the bottom field - that's three samples for 15 acres. Or - allow me to prove I can do math - each sample covers 13,612X your ickle beds.

The mineral test is essentially measuring base-line  or background mineral content.  Its unlikely that compost and other the other mostly organic additives you've added have altered that content.

So just take a tablespoon from each bed (about 6" below surface to avoid live organic material), mix together in a bag.  Done.  One test.

Now, if one bed performs wildly different go ahead and test that bed too.

And I applaud your approach - I work with the extension and soil district and find a lot of value, but I always have to remember that their tool kit does not include permaculture practices (well, maybe a little) and they have their pamphlets on spraying properly and adding stuff.  They're not bad people, but so much of what they do is built around "plow 'n spray" that they can't quite think outside that box (even if they want to).  So they can be right and yet wrong sometime, and other times just plain right.  Hard to know the difference sometimes...

I have used oyster shell instead of perlite/vermiculite with some success. Pumice also adds minerals as well as air/drainage to soils. Sharp river sand is also a good source of minerals and soil drainage. Geoff Lawton's suggested potting mix of 2/3 river sand to 1/3 compost has worked as well as expensive potting soil (Roots organics) for starting tomatoes. I agree that was a ripoff on Amazon, as I have found azomite for $18 for same weight, and its a local reputable supplier.

Ben Zumeta wrote:I have used oyster shell instead of perlite/vermiculite with some success. Pumice also adds minerals as well as air/drainage to soils. Sharp river sand is also a good source of minerals and soil drainage. Geoff Lawton's suggested potting mix of 2/3 river sand to 1/3 compost has worked as well as expensive potting soil (Roots organics) for starting tomatoes. I agree that was a ripoff on Amazon, as I have found azomite for $18 for same weight, and its a local reputable supplier.

Just..... to provide some insight....
Amazon will almost always be a lot more expensive on heavy items than a local garden/farm store because it will cost $12-$20 to ship the item.  Maybe less in cities that have Amazon driver delivery services.  But it is so much cheaper to ship on a pallet in a big truck (along with all they other farm items) to a farm store than a one off shipment of something heavy to a residence.

So you are paying for convenience and residential shipping when buying heavy items off Amazon.  So i recommend against it.... as long as you have a farm store within an hour drive.  But i wouldn't call that amazon price a ripoff.  They aren't price gauging.  Just covering their shipping for their Prime customers.

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To the original question.  This lady would probably say you just need to encourage soil life and that all the necessary minerals are already present in your soil ..... just not always in an 'unlocked' form:

"Dr. Elaine Ingham is an American microbiologist and soil biology researcher and founder of Soil Foodweb Inc. She is known as a leader in soil microbiology and research of the soil food web."

i believe that according to her... plants need such small amounts of minerals to be healthy and produce healthy food... and all soils have some of most/all minerals ... that even in depleted soils.... the solution is pretty much: Feed the soil life and they will unlock all your plants needs.

Dr. ingham is permaculture friendly.... if not a full-on permaculture enthusiast.  She was at Permaculture Voices 1.   She does classes and has some books on soil life as well. Pretty sure you can find lots of info online as well.  Good luck!

Jennifer Lowery wrote:I have 6 raised beds, all are similar composure.  I've only had one season (fall crop) with four of them.. added two new beds this spring.  Would it be good enough to sample just one of the beds or perhaps mix all 6 together and sample that?   I can't afford to sample all 6 raised beds as the local extension suggests.   They are only 4' x 4' beds.

Just for context, to add the trace minerals you would be looking for out of azomite you would be adding something like a cup or two to each of these beds, dusted over the top. If you can find the 40 lb bag for around $20 you are looking at a cost of several dollars total for the year. My only context for the efficacy of azomite is adding it to compost tea and it did SEEM to make the tea more active more quickly but I have never done a real scientific trial so I can't really say. Ultimately it is a very fine particle sized clay with lots of trace minerals present. In my experience it is a very affordable source of trace minerals.

Hi Jennifer!

I'd like to start my reply with my answer to the title of your thread you started. It depends. To some gardeners, the cost is worth it, and to others it may not be. I think the importance of inputs and the costs associated with them is something for each of us to decide.

Jennifer Lowery wrote:  I hear some people say the microbes can access the minerals and provide them to the plant.  Another guy says they can't be accessed and it is a quarry yard waste product cleverly marketed and is a gimmick and not worth it.

I want to offer a little information on these, starting with the first sentence. Yes, soil microbes do indeed make minerals available to plants. Here we're talking about water insoluble minerals and it is the soil bacteria and fungi that provide access to these minerals. In quick layman terms, certain soil bacteria can make and secrete mild acids which dissolve the minerals that are bound together into individual mineral atoms and also make compounds by either stripping away a particular molecule or combining particular molecules. In partnership with mycorrhizal fungi that live on and in plant roots in an area called the rhizosphere, they hand over and give minerals to plant roots. This is a very brief description, hardly worthy of the beautifully complex community of soil life, but there is much more on this subject authored by Redhawk, who has spent a career and lifetime studying soil. Here are a few links to some more information:

https://permies.com/t/86117/Bacteria-Fungi-Nematodes
https://permies.com/t/91663/talk-soil-minerals
https://permies.com/t/102935/soil-food-network-works

Here is the link to the gateway wiki to Redhawks complete series on soil: https://permies.com/wiki/redhawk-soil#637639

The second sentence quoted above, I'll start by saying the gentleman is in error by saying the minerals can't be accessed. The other part about Azomite being a quarry yard waste product may be accurate but I think saying it is a gimmick is inaccurate. The minerals that make up pretty much any rock can be made available by soil bacteria. Some rock dusts are more commonly used in agriculture than others, but there are quite a lot out there, from rock phosphates, basalts, even granite. Agriculture Lime is the dust made from crushing limestone and farmers all over the globe use it to adjust a soils pH and provide calcium to the soil for plants which those soil bacteria are making available.

I have used Azomite before and I also use rock dusts on my farm such as lime and soft rock phosphate, and I will share why. I have taken on the role of steward to my farm and I am on a mission to heal my soil, regenerate this tiny piece of earth and put minerals into the soil which will nurture life. One* of the best ways to regenerate and remineralize a soil that needs minerals is through rock dusts because they are water insoluble and will stay put. Rain will not leach these through a soil. The minerals dissolved from the parent rock dust particle will bind to soil colloid exchange sites and certain organic matters. Those are there to stay until needed by a plant, and those same bacteria and fungi will get them for the plant.

Rock dusts are becoming very popular as people both new to gardening & farming and those rooted in agriculture continue shift away from the conventional ways to better methods that heal and regenerate the soil, minimize pollution and erosion, and in turn give way to increased independence and profits.

* Minerals from the sea are the other best way to put minerals into a soil, through either kelp or unrefined sea salt such as Sea-90 mentioned in a post above.

Thanks for all the replies.  I have a lot of science to learn!  I wish I could find azomite locally but so far no go.  My local nursery acted puzzled when I asked about it over the phone.  I might be stuck ordering it from amazon for $40 for 40lbs.   I have no idea what kind of farming supply stores there are in Tulsa, OK.  I dont' know the names of the chains etc..  I am totally clueless.

Jennifer Lowery wrote:   I have no idea what kind of farming supply stores there are in Tulsa, OK.  I dont' know the names of the chains etc..  I am totally clueless.

Tractor Supply and Atwoods are two that i would check.  And then google organic and garden store Tulsa .... you may be pleasantly surprised.

Good luck!!

And maybe even Walmart... even if they don't have in stock you could possible order it from them online and have it shipped for free to their store.  Same with Home Depot.

before spending your hard earned money on soil stuff you might get in touch with your local ag extension agent, they are everywhere in USA and services are free, they will come to your property and test your soil and could even give you some great advice.

I get Azomite much cheaper than that as well.  I just look at it as insurance.  I use it and sea-90, but if I could only use 1, it would be sea-90.

I'll try Atwoods and Tractor Supply for the azomite.

I just ordered 4 lbs of Jobe's Organics Vegetable and Tomato fertilizer 2-5-3 NPK, it was only $7 from Amazon with free shipping.  Seemed like it was fairly good based on reviews.

I guess in the future I won't need to use an organic fertilizer product? i.e. if I have huge piles of homemade compost going, mulch during growing season along with covering the raised beds with leaves over the winter?

Anyone have experience and advice using azomite or other mineral sources as a free choice supplement for chickens or other livestock? I have read or seen both Mark Shepherd and Geoff Lawton use livestock as the vector for soil remineralization, but have never done so with raw ingredients myself. Instead I have fed them plants from soils i have attempted to improve with compost teas, passive fertigation from the birds’ runoff, and hugelkulture. Wondering if anyone has opinions about which spoke of the nutrient/mineral wheel you like to tinker with and why?

Minerals from the sea are the other best way to put minerals into a soil, through either kelp or unrefined sea salt such as Sea-90 mentioned in a post above.

This reminded me of an article I read a few years ago, maybe in TMEN, about a guy in Florida living on the coast. He was a retired doctor and decided to experiment with tomatoes. He built dozens of troughs filled with river rock and after starting the plants in soil, hung them with string so the roots were in the rocks. A few times a day he flooded them with seawater, which was then drained off. Using nothing but this flood system, he grew and sold tomatoes for years. The article was basically pointing out that every mineral and nutrient needed (at least for tomatoes, but likely everything) is available in seawater.

Minerals are part of the nutrient makeup of soil and required by plants. If your soil is deficient in one or more minerals, the plants may still grow, but will lack everything they need, which means if you are eating those plants, you also are lacking the complete picture. Ironically, a store bought carrot could actually be better nutrition than your organic carrot, if the carrot farmer is using soil amendments. All the compost and mulch in the world won’t create minerals. From all I’ve read and personal observation, I think the azomite dust is cheap insurance. If I could get kelp I would harvest a truckload a year to spread as top dressing.

I live in Wisconsin, where the glaciers stopped and dropped a bunch of ground rock on the soil.  Here it probably wouldn't be critical in terms of micronutrients.

That said, there is not really a down side to using it--the minerals break down VERY slowly in the soil and are only accessed through chemical action in the soil (organic acids in the soil) or also from worms. Worms have a gizzard a lot like birds do, and they eat bits of rock to help digest food.

Instead of azomite, some years ago I went to the big landscape supplier. They have these enormous piles of various kind of crushed rock--granite, basalt, limestone, marble...  I spoke to the people, and they let me take several buckets of the fines--the dusty stuff that runs off.   For them it's useless anyway--it's just the processing dust that comes from producing gravel from rocks.    Anyway, I grabbed about 5 gallons of each (bring at least 15 buckets--5 gallons of granite dust is EXTREMELY heavy!!).  Then, just dusted the beds with them.  Granite especially is made up a huge number of minerals and should really help to introduce a slow release micronutrient profile.

Their are other ways to provide micronutrients.  If you can't get rock dust, or don't want to pay for it, trees actually mine bedrock too.  Things like leaf mold can give the soil essentially the same thing.  

In any case, a little rock dust (azomite or other material) goes a long way.  You're just putting on a dusting--I actually used one of those Parmesan cheese shakers to sprinkle it lightly on the soil.  I sometimes use larger amounts in the compost pile too.  

I got interested in growing my own food several years ago, and ended up watching a lot of  "growing your greens"/John Kohler's youtube channel before I ever found this website.  Oh my gosh, if there were ever an advocate of using Azomite, it'd be John.  He swears his food is sweeter tasting due to the high mineral content from the rock dust.  He even does the brix tests to back this up.  Lately, he doesn't seem to be pushing it as hard, but I think he still genuinely believes it makes all the difference.

So because I watched a lot of his videos early on, I HAD to have it, lol.  I started out by broadcasting it all over my in ground growing areas and fruit trees the first couple of years.  I'd buy one bag of the pelleted Azomite for $17 here at the IFA store, and try to put it on the growing areas a couple/few times throughout the year, then go and buy another bag the next year, and then so on.  I don't know if it made any difference.  I had a lot of failures, and I didn't notice anything special about a sweeter tasting crop.  Keep in mind I was completely new to gardening when I first started using it.  I had nothing to compare against.  I also believe it takes at least a year for it to break down to a point where it's actually available for the plants to use.  So the first year of use, it does nothing from what I understand.  

I still buy about one bag per season.  Now, though, I put 100% of it in my deep litter (wood chip) chicken coop.  I believe it's okay for livestock to eat it (it's just rocks/minerals), and I'm guessing it's even better if they do ingest it and manure it back out to speed up the process of breaking it down.  My wood chip compost sits in the coop for about a year, and then I sift it out onto my garden beds.  I am super impressed with what my compost will grow now.  I'm not saying it's made any difference using the rock dust, but it certainly hasn't hurt anything.  My chickens are super healthy, and my eight year old leghorn is laying three to four eggs per week this year.  She stopped laying a couple of years ago, but now she's back at it.  I only know she's laying because she's the only chicken I have that lays a white egg.  My egg production in general has gotten better every year too.  

I will buy another bag next year......and the year after......
If I had easy access to seaweed, or granite dust, I would add those in addition to the rock dust.  I'm guessing the more sources of minerals the better the overall concoction in the end.

All of that being said, I have mainly clay soil here.  A lot of people say all the minerals a plant could ever need are trapped in that clay just waiting to be released.  I also live within a mile of a volcanic rock river.  I need to go out and start collecting all of that black "rock" gold, getting the sledge hammer out, and have myself a workout smashing that rock into free minerals!  

Ben Zumeta wrote:Anyone have experience and advice using azomite or other mineral sources as a free choice supplement for chickens or other livestock? I have read or seen both Mark Shepherd and Geoff Lawton use livestock as the vector for soil remineralization, but have never done so with raw ingredients myself. Instead I have fed them plants from soils i have attempted to improve with compost teas, passive fertigation from the birds’ runoff, and hugelkulture. Wondering if anyone has opinions about which spoke of the nutrient/mineral wheel you like to tinker with and why?

In the book Secrets of the Soil they speak with the man who discovered azomite (contrary to above comments it is not quarry waste, it is a certain kind of clay from a specific deposit in Utah. The company believes this makes it better than quarry fines.because the minerals are already in a colloidal form) and he swears by feeding it to livestock. Even says his cows once ate a whole 5 gallon bucket he left in.the barn.

I think if you are pasturing animals on large acreage then they are a great vector for mineralization. For.me, in a small garden setting with no animals, I like to add rock dusts to.the compost as its being built and use that as the mineral vector (including dusting rock dusts into the worm bin)

Three thoughts about alternatives to azomite.  The first is turkeys!  Joel Salatin talks about how turkeys are super beneficial for remineralizing soil because they eat so much gravel/aggregate and it is constantly being ground up in their gizzard as they eat grass.  He goes through hundreds of pounds of gravel as he raises his turkeys --- all that ground up rock ends up back on the land.  His soil tests before and after turkeys clearly showed that they had remineralized formerly deficient soil.

Yeah, I know -- that's not very practical.  Who has room for turkeys?

The second strategy is getting rock dust from a local kitchen counter fabricator/installer.  They cut slabs of marble and granite every day, and all that rock dust ends up in a slurry at the bottom of their cutting table.  I've carried away buckets and buckets of the stuff -- it's a waste product for them, so they are thrilled to get rid of it.  When every I make a new raised bed (4' x 12'), I get a 5-gal. pail of that stuff and mix it into the soil.  That adds more minerals than the plants in those beds will use in a long, long time.

The third option is to throw a generous shovel full of gravel/aggregate into the bottom of your huglekulture or huglebed.  When I build a raised bed, I excavate under the soil line about 10 inches or so, and fill that lower space with logs.  Then I toss a generous amount of gravel down on top of those logs.  Why?  Fungi "mines" rocks and breaks down the minerals to make them available to plants above.  Over the years, the fungi that populate those logs will "eat" the rocks and feed the minerals to whatever plant roots that might be asking for them.  Yes, this is much slower than just dumping a scoop of azomite onto the soil surface and watering it in, but it mimics nature more accurately.  

For azomite, rock dust, green sand etc.  If your soil needs the micro type of minerals these I use.  Generally in soils low in clay might need this.

I like to think, short, mid and long term mineralization.  It is important to know your soil and understand how you affect your soil and how to slowly work it in positive directions.  This is benefit does not come at the flick of the switch if you do not take into account all the factors that enable this source of minerals to be utilized.

Rock dust and similar does nothing for your plants this year but for the future over time.  Think of it like the Japanese say, Kaizen.  Essentially, small imperceptible changes that over time make big changes or improvements.  This helps keep brix consistent but is only part of the equation.  It really depends on your soil management and grow style/plan, soil management, and the environment.  

I think it is fine for most people here who are not using chemicals as the soil life is necessary to break that rock down and make useable for the plants.  As stated, good soil life and carbon are also essential parts of that equation for it to be of use.

Adding to worms for grit and to compost I always do.  

No need to go crazy generally but as some have already said, determine after soil test but all things simple Just give sprinkle in the spring and is already in the compost and worm castings.  Seawater and fermented seawater are great for adding maintenance minerals.  

For positive microlife I love to use natural farming techniques, worm castings, composts of varied types from leaf molds, decomposer (mushroom) compost and sea and forest composts.  Biochar I love as it helps stabilize the microlife as like fortress homes that helps during periods of soil stress.

I believe in it but only if used effectively and overtime.  Not all soils need it and is point of no return to potentially causing lockout issues if heavily over done but mostly when done like that it is just a waste of money.

I see it as a soil tool.  Like all tools, it depends on the need.

just found there is an old book somewhere on his called, "Bread from Stones."

One thing I’ve noted recently is that azomite is fairly high in magnesium. In my area, like many other rainy coastal regions, magnesium is in excess and calcium is deficient. I am leaning into using more oyster shell because it is the best magnesium free calcium source I know of, but have still use azomite in raised beds. I mix it 1/2 and 1/2 with glacial rock dust, which also has Magnesium, but the plants and soil look happier and my young trees look good.

Hi There,

If you want a cheap alternative, just use rock dust from any quarry, its dead cheap and great for the soil.

If you can access rock dust from various quarries all the better as there is normally a different make up the minerals.

Cheers
Anthony