What are you looking for...phenominal growth? More nutrients?

Unless your soil is a poor sandy soil, you may not see a huge difference. Also some minerals may take a couple years to become absorbable.

I use a modest dressing for ensurance sake. Mine plants do excellently.

My garden is very sandy, water retention is poor. For the last 4 years I have puts lots of coffee grounds, and about 200 bags of leaves on each year., In a 50 x100 ft. plot. About half of those leaves are used each year on approx. 1/5 of that area for rotating plots of tomatoes. I have been mulching with hay. I have to water the tomatoes on average every 5 days. This for me is great retention, They have been doing great from June till august then seem to run out of steam. I feel that I'm leaching the sand and am hoping some rock dust may improve my crop. Its not been terrible , but I feel I could do better. My other crops, potato , peas, beans and corn do fairly well . I mulch approx. 45 bales of hay between the potatoes and tomatoes and turn them it each fall. With my rotation of 3 years before the plots are replanted I think much of my O M is depleted . I'm looking for some insurance as you stated , and maybe some improvement. I suspect twice as many leaves would be better however I lack the energy and time. I'm planting 75 tomato plants on a 44 x 28 ft. patch and last year processed one way or another about 300 quarts plus all we (4 ) could eat fresh and the normal give away to friends. I now have a chipper shredder and plan on adding wood chips to my composters. I think that will help a lot.

Keith, how deep is your sand? I used to garden on sand that was 23 feet deep, according to the local soil conservation guy. Everything grew great, but my veggies were pretty tasteless. Even watermelons had no flavor. I put a lot of leaves on, but everything would rot and wash into the sandy subsoil. It was pretty hopeless.

Maybe the best thing to do is to get a couple of loads of loam and till it in, or just spread it on top. I don't think the rock dust is going to do anything. If your sand is deep, the loam will eventually disappear into the subsoil, but it will take a long time.

My sand is no less than 5 feet ,and have found no spots deeper than about 10 ft. Beneath it is what we always called hard pan. It runs from 18 inches to 6 feet thick that I know of.

I would try the loam. Don't bother with the rock dust. The concentration of nutrients isn't high enough to do anything.

I grow in sandy soil both in FL and MA, and having plants - especially tomatoes - "run out of steam" later at some point is common. I can see the contrast to other much better soils where I help out a farmer friend, it is indeed very marked. The soils with a lot of clay and silt the crops do not suffer that semi-collapse later in the life cycle.

I have not come up with a total 'fix' as of yet (and I doubt there is one). Careful irrigation helps but does not begin to equalize. I have tried different rock dusts and azomite - the latter has quite definite results but I doubt it is fully worth the expense except perhaps in extremely de-mineralized situations like FL sand.

Last year I tried azomite on 1/2 of a raised bed. I use the very fine powder kind, mixed it with water then applied to just one side of the bed and waited. Within a week there was an impressive difference. Granted it was only buckwheat cover crop.
Since then I apply it monthly during the growing season. I also use my own compost and ground leaves to supplement the soil I have lugged in.
I also have a fish pond and collect the filter waste to apply to everything through out the year. Even when I don't have anything growing, I still flood the beds with fish waste water.
I use it for my trees which grow in sandy,rocky ground. I have queen crepe myrtles and get great flowers and growth. Ironwoods are very full and pushing a lot of new growth and berries for the birds.
I apply it to roses. They are in the ground but super amended soil.
For my needs, rock dust has been very helpful.

I have also been looking at azomite , and something very similar called Ruby Mountain Rock Dust. To hear these last two posts is very encouraging. Pnbrown I certainly see your point on expense, however your remark " definite results " is reinforcing my temptation to try it. How much do you apply? Soflaj, I assume you watered the other side of your raised bed as well , just no azomite? If so your results are adding to my urge to pull the trigger finger on a couple of bags of this stuff.

Yes I watered the non treated side. I bought a 44 pound bag in Early 2014.
I won't need to buy any this growing season. A little goes a long way.
I use a 5TBS scoop, not full to the top mixed in a gallon of water, monthly.

You know that you can buy smaller amounts on AMZ...

Or if you know someone, they might share... :)

Depends some what on which rock is ground. The common ground limestone is rock dust. as is the common Dolomite. Azormite is a bit more rare but is a specific ground rock. It does contain a high level of trace elements. Granite varies in composition ove 70% of is Silicon dioxide, with varying amounts of Aluminum oxide, potassium oxide, Sodium oxide and and other metallic oxides in smaller amounts.

Presently I'm leaning towards using Brix Blend Basalt or, Basalt Micro Fines. Anyone have any experience with them?

jonhughes, You are a breath of fresh air here. Much suspicion and fear seems the order here when it comes to supplementation of our soils. Granted, a bit of wisdom is necessary.

Hey, why stop with healthy soil. our bodies need minerals ,herbs, enzymes, vitamins, anti-oxidants, and more....all the more so as we age.

soflaj -- great to read the results of your mini experiment! I've been using Azomite for a couple of years, but don't know what it's done since I just throw in on every bed.

Jonhughes -- thanks for posting all that great info. Who knew about capillary action???

"Within a week there was an impressive difference."

It is a biological impossibility that 'rock dust' caused any difference in growth over that time frame. The End. Some guy on the internet hypes rock dust, and suddenly it's magic fairy dust for gardening. It's a huge waste of money. Get a soil test that includes micronutrients. If you do find that something is below proper levels, buy some and add it to your soil. Otherwise, add organic matter and see REAL differences in growth.

This person needs organic matter, not inorganic. Peat moss, compost - that's the ticket.