What’s my soil type?

Melbourne has various soil types, causing vastly different results in plant growth in the regular suburban and rural garden.

Before you plant, it is best to find out what type of soil you have so you can adjust the soil to suit your plants or adjust your plant selection to suit your soil!

 

Why is my soil type important?

Your soil can dictate what you’re going to be able to plant in your garden. Before any major work is carried out (that includes landscaping AND building too) a soil test is taken. This is to find out the reactivity of your soil, what nutrients already exist in your soil, pH levels, drainage and runoff just to name a few.

If you have poor drainage, for example, plants that suffer in boggy, wet soils would be a poor choice. Plants that require lots of water planted in sandy soils could cause you to have very large water bills due to the increased drainage of sand versus clay or loam.

 

If you want a very comprehensive diagnosis of your soil there are professional soil testing facilities throughout Melbourne. For the everyday gardener, you can do some very commonly used, basic tests that will tell you enough to get you started.

 

But first, you will need to know what your soil is trying to tell you visually!


You can tell quite a lot just by looking at your soil. So before you get your hands dirty, have a quick squiz at your soil and look out for these two features.

 

Soil colour

The colour of your soil usually refers to what minerals are present in the soil. A dark brown or black soil will usually have high organic matter; rich orange-brown or yellowish-brown soils will be higher in iron. Brightly coloured soils are also known to drain very well whereas soils with mottled greys, reds and yellows will often be soggy and wet.

Soil TextureHello Hello Plants Melbourne Victoria Australia Soil Particle Sizes

Soil is usually made up of clay, silt and sand. Each of these soil particles are categorized by their size and depending on the percentages of clay, silt and sand in your soil, it will give you the soil texture.

 

There are 12 soil textural classes. They are often represented on a soil texture triangle so that each of the terms like “silt” or “loam” will always have the same meaning. You may have seen this triangle many times before!

Hello Hello plants melbourne victoria australia soil pyramid


Now to get into the real dirt!
To find out what type of soil you have we need to try a few of these basic tests.

pH test

Hello Hello Plants Melbourne Victoria Australia Close up of pH soil test slightly acidic

pH soil test showing a slightly acidic soil

pH is the level of alkalinity or acidity in your soil. To learn more about pH and what it means for your soil, click here

You can purchase a pH testing kit from your local hardware or some nurseries.
They’re very simple and easy to use. They will give you a rough idea of what pH level your soil is at.

 

 

Ribbon Test

Hello Hello Plants Melbourne Victoria Australia Soil Test Ribbon Test 3 stages

Roll your soil sample between your fingers and try to make a roll of soil

Drainage test

  • Dig a hole approximately 30-40cm deep and 15cm wide
  • Fill with water and time how long it takes to drain

If the water sits in the hole for over an hour with no recognisable reduction, this is poor drainage.

If the water level has dropped a few centimetres after an hour or so, it is moderately well drained

If it drained straight away, that’s very well drained!

 

Mudshake or Jar Test

Hello Hello Plants Melbourne Victoria Australia Mudshake or Soil Jar TestWhat you will need:
  • Large jar with a lid (that seals well!)
  • Soil sample (you will need soil UNDER the leaf litter and topsoil. Dig a hole in the garden bed and take that soil as your sample otherwise you’ll get too many leaves and sticks in your sample!)
  • Water

 

  1. Fill a the half way up with your soil
  2. Fill the jar with water leaving a 1cm gap of air at the top
  3. Shake very well (approximately 30 seconds)
  4. Leave, undisturbed, to settle overnight or for a few hours

 

Hello Hello Plants Melbourne Victoria Australia Mudshake Soil Test Jar Soil Test sections labelled clay silt sand

Once the soil sample has settled, the layers become clearer

The soil sample will settle in different layers, separating the clay, silt and soil (and organic matter if there’s a bit in there.
The sand layer will be at the bottom, then silt, clay and lastly any sticks, leaves or large chunks of organic matter (hopefully there’s none if it’s well dug soil sample!)

Sometimes it can be difficult to differentiate between the layers because you may have almost no silt in your garden or almost no sand! So the layer won’t be very thick. If you can, do a few samples to compare and to practice.

Once you have your layers, estimate a percentage for each section.
When you have your estimated percentages, compare them to the Soil Textural Triangle below and voilà! You’ll have your soil type!

Hello Hello plants melbourne victoria australia soil pyramid results