Rock Minerals

Rock minerals are not just crushed rock as most people think but are really a carefully blended mix of minerals such as Basalt, Gypsum, Lignite & Rock Phosphate.

There can be up to 100 different minerals present but most are as very small amounts of trace elements and their use will create a reserve of these trace elements.

The common minerals supplied by Rock Minerals are Potassium, Calcium, & Magnesium but this depends on the natural mix of the rocks that they are derived from & mixed with to form the commercial product.

They may be in small amounts but trace elements need to be in small amounts otherwise they become toxic to plants even though they are essential to plant (& human) health.

Some trace elements are:

  • Manganese (Mn) It helps in the formation of chlorophyll
  • Iron (Fe) Important in forming chlorophyll
  • Boron (B) influential in the absorption of calcium
  • Molybdenum (Mo) Important in Nitrogen Fixation (especially in Legumes)

When plants are grown in a garden they use up the available nutrients which then need to be replaced – hence some form of fertilisers are used.

Some fertilisers are fast acting (eg most chemical fertilizers) while others are slow acting, usually as they are largely insoluble as are Rock minerals.

Unless the garden plant receives the nutrients in the correct amounts and at the time they are needed (eg. germinating or flowering or fruiting) they will not grow at their desired maximum rate.

A plant that is deficient in any one nutrient will not grow or fruit up to its potential & their fruit will also be lower in the element and therefore not be as nutritious to the person eating it.

The mix of natural mineral rocks are ground up into very fine dust & then often compressed into prills (small balls of compressed material) to make them easier to scatter.

When wet they dissolve into fine dust again. The smaller each particle of Rock mineral then the LARGER is its surface area. ie the LARGER the area per cubic yard for the soil fungi & insects, water, sun, etc to act on it and break it down & release the nutrients.

The speed of break-down is all relative compared to a soluble chemical fertiliser so natural Rock minerals are in effect Slow Release Fertilisers that have parts that may not completely break down & release their nutrients for up to one year.

This is why they are NATURAL fertilizers so are applicable to organic plant growing & so are safe to use on Australian Natives (some of which are sensitive to Phosphorus as they have an extra root system to take up all the available Phosphorus from the soil)

Rock minerals are usually applied at the rate of a generous handful per square metre both at planting & again in Autumn & Spring as a side dressing.

Due to them being almost insoluble, they are not leached out of the soil so are excellent for sandy soils.

Where you only have one time to apply rock minerals eg into the planting hole of a big plant (ie a citrus tree) then more would be used than if only top dressing the garden.

When Rock minerals are added to worm farms or compost, the added nutrients are also added to the garden plants with the worm casts or compost.

Today’s Did You Know…?

You can use Bicarbonate of Soda (also known as Sodium bicarbonate) to:-

  • Get rid of fish smells by soaking the raw fish in 1 litre of water with 2 tablespoons of Bicarbonate of soda for 1 hour.
  • Clean off garlic or fish smells from your hands using 2 teaspoons of bicarbonate of soda instead of soap.
  • Fluff up an omelette using ½ teaspoon of Bicarbonate of soda per 3 eggs used.
  • Clear a blocked drain with 1 cup of Bicarbonate of soda followed by 1 cup of hot vinegar (I’m sure you all know this one)
  • Use as a fire extinguisher for stove or car fires using a few handfuls of bicarbonate of soda even on electrical fires as it is dry