Rock Dust Fertiliser for Plant Health

magnolia LIttle Gem Rock Dust


Add Basalt rock to your garden. It’s volcanic and chokkas full of minerals.

Rock Dust Fertiliser for Nutrient Dense Plants.

The only supplementary gardening products we promote and sell is stuff we actually use in the nursery for growing and maintaining the plants to the standard that you see out here.  As well as what we use in the gardens that we maintain.

We make our potting mix for the nursery out of select raw materials.  In our own garden, we use a quality, composted soil conditioner to plump up our existing soil which grow our plants   One special ingredient we add to both potting mix and soil conditioner is Rock Dust.

We stumbled upon Rock Dust quite by accident, years back,  while ordering some road base for a new section of nursery.  Upon overhearing a vineyard operator asking for ‘fertiliser dust’  – found out what it was and proceeded to order 10 m3 as a trial,  adding it to our potting media. It didn’t take long to see results.  Plants were stronger and healthier, and customers started to comment on the health of their plants purchased from us, months after putting them in the ground.

Jack’s been using it to top dress the lawn, after a clumsy spill on the grass produced a brilliant green colour within a week!

What is Rock Dust?

It’s not a true fetiliser as it doesn’t contain NPK. It just commonly gets called ‘fertliser’ .

Rock dust is Volcanic Basalt Rock. The name Rock Dust sounds magical and if there was a miracle product, this would be it.  On top of the real life results we’re seeing in our plants here in the nursery, we’ve been doing a bit of reading as to why it’s so good.

Rock Dust is ground up volcanic rock, sand like in texture, that holds water, and adds lots of goodies that are instantly available to all plants – fruit trees, vegetables, natives, exotics, trees and palms, even proteacea (such as Grevillea, Banksia, Protea and Leucadendron) will all benefit from the addition of this product.

As you already know, volcanic regions produce some of the most mineral rich, nutrient dense soils on Earth.  Rock Dust is full of minerals and trace elements  ( micro and macro nutrient) that are lacking in our dry infertile, sandy soils. Rock Dust  helps us to build the soil structure, buffer the pH, retain moisture as well as encourage healthy soil organisms which have a mutually beneficial arrangement with plants – they help plants access more nutrients and water – and  in turn, these microbes get their sugary carb fixes from plants.  Rock Dust improves the Cationic Exchange Capacity (CEC) of soil. Soil then becomes adsorbant –  meaning the soil holds onto and chemically binds nutrients like nitrates and phophates in for plants to use, rather than being leached away.


Add Rock Dust to Your Soil

Add Rock Dust to composted soil conditioner and you have yourself a great all round planting mix.  And you’ll see the results in your garden with lush, healthy plants and nutrient dense fruits and veggies with superior flavours. You can sprinkle some into your already established gardens at any time.

Talking to you in the nursery, we find that those of you living on the coast are quite disheartened to have to contend with sandy soil on your house block- and often have trouble establishing a garden.

What we’re living on is a strip of land called The Swan Coastal Plain . It’s about 30km wide and runs up and down the coast, North of Perth all the way down South to Cape Naturaliste. This land is mostly sandy, infertile and highly permeable which means that it doesn’t hold much water. While there are thousands of unique, local endemic species that have adapted to this type of ground over many years, this vegetation has mostly been cleared for farming or development.

If you’re in a new house in a newly built suburb, this sandy substrate, gets cleared of any natural top soil, with yellow builders sand plonked down on top.  Furthermore, this infertile sand has tendencies be hydrophobic. ie – water repellent . The theory is that sand here in Western Australia is coated in a wax like substance leftover from plant residues, and microbial byproducts, that prevents water from actually seeping into the soil below.  No doubt, you’ve seen this before. Water runs right off the soil instead of penetrating into the soil beneath.

To remedy this, build up your soil structure using composted soil conditioner, make sure the soil conditioner that you purchase is not diluted with sand. (don’t need more sand!) Good Soil conditioner  is comprised of well composted organic material called humus and is a breeding ground for the microbial good guys – essentially bringing your soil and garden to life. Adding mulch keeps your soil moist and microbes alive while also adding more organic matter to the soil. Use a wetting agent  if your soil dries out.

If you build your garden soil this way, you can grow a wide variety of plants.

By the Way, there’s one advantage to all of this sandy soil. It’s easy to dig to work in soil conditioners and clay and is also free draining!

Where Can I Get Rock Dust?

Rock Dust is produced locally from volcanic rock deposits found nearby. We have access to Basalt Rock right in our own backyard!  5 minutes away from us, across the highway, in Gelorup, ( Bunbury ) there is a Quarry that mines this Basalt rock. They use it to produce the blue metal, gravelly stuff of varying aggregates for road construction to use loose for your driveway, or hot-mixed into a highway.  Rock dust is actually a by-product of this, called blue metal fines.

basalt rocks in Bunbury - rock dustIncidentally, this rock dust is from ancient lava flow that formed around 130 million years ago when Australia was separating from India and Antarctica. Pictured here are basalt rocks at Bunbury’s Back Beach.This area used to be the site of a basalt quarry from 1890 – 1951 with gravel used for road construction.


We keep a pile of Rock Dust to sell by the scoop – bring your ute or trailer – you don’t need much – and it’s pretty cheap –  $35 will get you a tractor scoop which goes a long way. (cheaper than sand!) or come and grab a bag and shovel and fill yourself – grab some clay and compost as well.

We also have an awesome product Soil Saviour

avail for you to add to your sandy soil to create a beautiful fertile soil – you can grow just about anything in this mix. It contains Rockdust, compost with biochar, clay, and zeolite. This is sold by the bag here at the nursery.

basalt rock dust



It’s basically the rock dust, with other added essentials that your plants will love – It’s got some added ingredients that help to break it down so that it is readily available for plant uptake –  A Great product. It’s easy to apply by the handful – with a little going a long way. 

Our Soil Conditioner is also available by the tractor scoop or by the bag. We sell it for $45 per tractor scoop which is soil organics plus BioChar. Clay and rock dust mixture also  avail in tractor scoops for $55 for a 1 mixed scoop. Or  $45 per scoop when getting 2 scoops . Bring your ute or trailer.

This post is an update . OP April 2015.