Tell me what you know about Rock Dust

Okay...I'll admit it...I'm a big fan of John at growingyourgreens.com

It just seems like the guy has some really good tips, not to mention that he is a SERIOUS S.F.G.-er. I've heard him talk a lot about rock dust, so I started investigating. I grew up farming, and most of my family are still farmers, so this topic (soil mineral depletion) has always intrigued me.

I'm sold on the science behind it, but clueless about where to find it. I would REALLY like to add it to my beds, but don't know where I can get my hands on some. I'm certain that it would lead to healthier food in depleted soils, so I'm itching to try it.

Has anybody here ever added it to their "mix"? If so, how were your results and where did you get the dust? Any info anyone has would be much appreciated.
-Pisachi

John's favorite brand of Rock Dust is Azomite (Azomite is actually a trademark brand for a specific type of rock dust mined in Utah)

Texas suppliers of Azomite are listed on Azomite's website....here at...

Texas Azomite

My "testing" was done very unscientifically, so take the results with a grain of salt. I saw no real difference between growth and yield in a rock dust treated bed and one that wasn't treated. Overall plant health seemed better, but that could have been because of any number of reasons. Having said that, I will probably continue to use rock dust just because of the extra source of minerals(but I don't treat it as one of the five composts either).

Things that have changed since I used azomite: I now produce enough of my own compost to supply the "one scoop" between harvests either through my compost bins or worm bin(therefor I know what's in my compost). I now use drip irrigation, which makes a huge difference. I started to add mycorrhiza in random squares. I try to start seeds in the garden instead of transplanting(less soil disturbance). I also spray fish emulsion twice a season.

Also, Mel's Mix seems to get better with age(which any 'soil' should if you're doing it right). So as you can see, it may not have been the azomite that gave me the edge, but that won't stop me from increasing the fertility of my MM with it. I also got my azomite from amazon.com. Sure the shipping is prohibitively expensive, but that's the only way I can get it.

Other ideas on increasing the fertility of my MM is to use clover for a living mulch. I'm not sure how well that will go, but I'm going to find out!

I know this isn't going to help any of us here in the US, but rock dust is recommended by the organic farm teacher in Puerto Princesa, Palawan, Philippines. There they just go to the river and pick up quartz stones and take them to the rock grinder. He grinds them up.

Kay

I have a difficult time finding Azomite here on the East Coast. I use Redmond Conditioner instead with great results. They advertise it as a feed additive but if you look at the analysis it is similar to Azomite. My local nursery sells it as an alternative to Azomite.

If you go here and scroll to the bottom you will see it.

http://www.redmondnatural.com/products

I post this for those who can't find another source you may be able to find this at feed stores as a substitute.

I am a huge fan of John's as well. I also feel the greens grown with rock dust tend to end up much sweeter and tastier. I add it in similar quantities to what John does.

The huge 55 pound bags of Amozite are way expensive to ship...so another option available to you if want to experiment with rock dust and can't find it locally is to buy the much smaller 2 pound bags of stuff online from somewhere like Amazon.Com and use a handful to boost your compost tea or add the whole 2 pounds too your finished compost pile.

CharlesB...You, sir, are a genius!

I don't know why that never occurred to me. We used mineral licks and bagged minerals all the time growing up on the farm. I never even made that connection until now. I'll bet I can get a 50 lb. bag from our local feed store for $20. GENIUS!

I'll grab one of those tomorrow, and it will be in all my beds by wednesday.

I'm guessing that it won't make the fruits or veggies any bigger, but I suspect it will make them more nutrient dense. That's what I'm after with it anyway...healthier food from healthier soil.

Thanks,
-Pisachi

Thanks for all the good info, ya'll! (Yes, ya'll is a proper grammatical term here in Texas. LoL!)

I used the Azomite link, but there were no sources close to me. However, I'm sure I can get bags of mineral fairly cheap from almost any of the feed stores around here. That's my plan of action now.

I'm thinking about leaving it out of one of my beds, and then growing a "test bed" next to it. Plant the same veggies in both beds, and then analyze them later for mineral content. (I can't help my "scientific method" nature...I'm a science teacher after all)

Either way, I'll report back in a few months and let you know how it turned out.
-Pisachi

There is another product often called basic slag . it is the scum taken off steel furnaces and ground to dust.

The theory being that it is similar in make up to what comes out of volcanoes and we know from many observations that plants grow like mad in cool moist volcanic dust as it has almost all the nutrients needed for growth

Be very careful using livestock minerals. Read the labels carefully. Most have added salt to regulate the animals intake. And some can have high levels of heavy metals.

Didn't know about the heavy metals thing. Thanks for the heads-up. I am a pretty big stickler about heavy metal toxicity. Is there a way to tell which ones are alright and which are not?

Pisachi wrote:Didn't know about the heavy metals thing. Thanks for the heads-up. I am a pretty big stickler about heavy metal toxicity. Is there a way to tell which ones are alright and which are not?

Livestock minerals are formulated to be fed to animals to prevent and treat for deficiencies depending on what else they are fed.

For instance, I raise dairy goats and in this area we have problems with copper deficiency so we have to use a mineral that is very high in copper because of the higher levels of molybdenum, sulpher and several other minerals in our feeds. Different species, feeds and areas all require different added minerals, there is no one size fits all.

And nearly all of the mineral mixes I am familiar with contain added salt. I try to make sure that I do not add leftover minerals to my compost pile when I clean the feeders & pens.

I've looked through the book and can't find anything about this, so why doesn't Mel address mineral deficiencies? How do I know if my SFG is lacking in certain minerals. This is confusing. There are different types of rock dust that provide different minerals, and some change the pH. What to do?

Yus, Mel keeps it simple for folks. If you were successful in getting 5 different types of compost, you will probably have great success in the garden. Amendments such as dried blood, bone meal, gypsum, lime, wood ash, rick dust, these things aren't necessary in the Mel's mix unless your plants are showing they need help. Many of these amendments are sold for gardeners and farmers that have depleted soils.
Consider this a learning year one, there is no way to know everything. Keep reading and your garden will guide you. What to do? nothing, watch, read and learn.

Ahhh thanks camprn. I keep forgetting that we don't have to worry about 'depleted soil' since we're not using soil. duh!

Yus wrote:Ahhh thanks camprn. I keep forgetting that we don't have to worry about 'depleted soil' since we're not using soil. duh!

BINGO!, See you are learning!!

Hahaha! Sorry about that Yus. I didn't mean to worry you. Perhaps I should add that "Mel's Mix" has never failed me. However, I'm an experimenter by nature, always looking for some way to tweak this or that...and my garden reflects that. Every season I have two or three different experiments going on.

For example, last year in one bed I ran a drip line down the middle to test the hydrotropism of different plant roots. I also experimented with three different kinds of mixtures/soils for starting plants from seed.

However, the one you might be most interested in was this: I experimented with planting okra in three different places to test the efficacy of the SFG method. One batch I planted in a raised bed with Mel's Mix, one in a raised bed with regular soil and a wood chip mulch covering, and one straight into the ground like a regular old garden. The results were astounding. Before I tell you the results, I should probably qualify them by stating that last year we had record setting drought and heat here. I'm assuming those conditions probably exacerbated the results a bit. Nevertheless, here is what happened:
1. The okra in the ground died, most likely because the ground was so dry and cracked, almost no water could stay in the root zone of the plant long enough to be absorbed. There were cracks in my yard wider than a quarter. By that I mean wider than a quarter width- ways, not held on-edge. (Lots of clay in the native soil here)

2. The okra in the soil/mulch raised bed was very stunted (I'm guessing for basically the same reason). They grew to somewhere between 1 1/2 to 2 feet tall, and produced very few okra pods.

3. I know this will sound far-fetched, but the batch in the raised bed & Mel's Mix grew to almost 8 feet tall, and put off so much okra we couldn't eat it all. It was a 4x8 bed full of okra, and I had to go out and harvest it every 2-3 days. I cut the bottom out of a 2-liter bottle, and would fill almost 2 of them every 3 days or so.

Perhaps that little anecdote will quell some of your apprehensions. Happy growing, man!