Basalt rock dust as plant fertilizer

One of the most valuable soil amendments and organic fertilizers is volcanic rock dust. Granite rock dust is one example, basalt rock dust is another.

How basalt rock is made

Basalt rock dust as a source of natural nutrients for plants

Basalt is an igneous rock. That means it wasn’t processed or transformed by environment, so the plant nutrients in it, are just as they were when they came out of the center of the Earth. No trace elements or micronutrients were leached out of it. That’s why using this volcanic rock as a fertilizer provides your plants, animals and you with great health benefits.

What macronutrients, micronutrients and trace elements are in rock dust? Basalt rock dust chemical composition

No two basalts rocks are created equal, but they have a lot of similarities. One of them is that they contain a lot of nutrients that is needed for your soil!

Chemical composition of different basalt rock dusts

Chemical composition of different basalt rocks in Brazil. All basalt rocks have somehow similar composition, although they are not identical.

How to use basalt dust in the garden?

To use basalt dust in your garden it’s good to spread it on top of your beds or in your orchard. It can also be used on the lawns.

Minimum recommended application rate (for the first time) is:

3 tons/acre = 14 lb/100 sq. ft. = 1.25 lb/sq. yd.

or (metric)

7.5 tons/ha = 750 kg/1000 sq.m = 75 kg/100 sq.m = 750 grams/1 sq.m

But a rate even 8x higher can be used, although it would have to be incorporated into the soil and it would be on a pricey side if you were to buy (and transport) your rock dust.


My experience with basalt rock dust

I’ve been using rock dust on my experimental patch in UK and the results were good. My greens were growing very well, they were stronger and they tasted very well.

I was using adding approximately 1 kg/1 sq.m  (20/ 100 sq. ft.) every 2-3 months as top dressing for my garden.


Check out this short video:

Leave a Reply