Improving your soil

Good soil is the foundation of a healthy waterwise garden, the healthier your soil the more drought resistant your plants will be.

Sandy soil, commonly found in WA, has a low water and nutrient holding capacity. Here are some handy tips on how to improve your soil:

  • Apply a soil improver with a wetting agent at the start of winter rains, in early summer and as recommended by the manufacturer.
  • The easiest time to improve soil is when planting, when it can be thoroughly mixed with the top 30cm of soil.
  • Apply soil improver from the top to an established garden by spreading a layer of compost and then a layer of waterwise mulch.
  • Always water in wetting agents until they foam. This means they are activated and doing their job. To make the most of your wetting agent apply a soil improver and waterwise mulch.
  • Add organic matter, also known as compost for healthy plant growth
    • Animal manures, worm farm residue, bagged soil improver and soil conditioners are all good sources of organic matter
  • Add soil amendments, also called clays to improve water and nutrient holding capacity   

Watch this video about improving your soil through the use of wetting agents:

Read a transcript of 'Improving your soil with wetting agents' (new window)

Watch this video about improving your soil through the use of clay:

Read a transcript of 'Improving your soil with clay products' (new window)

Soil improvement in the regions

Soil types across Western Australia vary greatly and to keep your soil healthy, it's important to understand the soil characteristics that might apply to your region. While some local native species of plants will grow in natural soil without any soil improvement, most still benefit from it, especially during the establishment phase. Planting most exotic species in the regions will require soil improvement prior to planting.

Soils in the Great Southern Region vary from deep sands to sandy peats, loams and clays and complex duplex soils where one type sits on top of another.

Some characteristics of Great Southern soils

Soil type  Becomes non-wettable  Water holding capacity Nutrient holding capacity Benefits from organic matter Benefits from soil amendments
Sand  Very commonly Poor Poor Greatly Greatly
Sandy loam Occasionally Medium Medium Greatly Some
Clay Very rarely Good  Medium Greatly A little
Rocky or stony soils  Occasionally  Medium  Medium Greatly A little
Potting mix  Very commonly  Good  Good N/A A little

Soils in the Mid West region range from deep sands on the coast to sandy peats, loams and clays, and complex duplex soils where one type sits on top of another. There are also areas of rocky stony soils.

 Some characteristics of Mid West soils

 Soil

Type

Becomes non-wettable 

Water holding Capacity

Nutrient holding capacity

Benefits from Organic Matter

Benefits from Soil Amendments

 
Sand Very commonly Poor Poor Greatly Greatly
Sandy loam Occasionally Medium  Medium Greatly Some
Clay Very rarely Good Medium Greatly A little
Rocky or Stony soils Occasionally Medium Medium Greatly A little
Potting mix Very commonly Good Good N/A A Little

The most common soil types within the Kimberley town boundaries vary from sand, sandy loam and rocky stony soils. Black cracking clay is also common.

 Some characteristics of soil in the Kimberley

Soil type Becomes non-wettable Water holding capacity Nutrient holding capacity Benefits from organic matter Benefits from soil amendments
Sand Very commonly Poor Poor Greatly Greatly
Sandy loam Occasionally Medium Medium Greatly Some
Clay  Very rarely  Good Medium Greatly A little
Rocky or stony soils Occasionally  Medium  Medium Greatly  A little
Potting mix  Very commonly  Good  Good  N/A A little 

Soil types in the South West vary greatly. Common soils include the deep sands on the coast to sandy peats, bare rock, gravel, loams and clays, and complex duplex soils where one type sits on top of another.

Some characteristics of South West soils

Soil type Becomes non-wettable Water holding capacity  Nutrient holding capacity Benefits from Organic matter Benefits from soil amendments
Sand Very commonly Poor Poor Greatly Greatly
Sandy loam Occasionally Medium  Medium Greatly Some 
Clay Very rarely Good Medium Greatly A little
Rocky or stony soils Occasionally Medium Medium Greatly A little
Potting mix Very commonly Good Good N/A A little

The most common natural soil types in the Pilbara are sand, sandy loam and rocky stony soils. In some areas the soil is strongly alkaline with a pH level of 9 or above.

Some characteristics of Pilbara soils

Soil type  Becomes non-wettable  Water holding capacity Nutrient holding capacity Benefits from Organic Matter Benefits from soil amendments
Sand Very commonly Poor Poor Greatly Greatly
Sandy loam Occasionally Medium Medium Greatly Some
Clay Very rarely Good Medium Greatly A little
Rocky or Stony soils Occasionally Medium Medium Greatly A little
Potting mix Very commonly Good Good N/A A little

 

Soil types in the Goldfields region include sand, gravel and clay, with the most common combinations being sandy loam and loamy clay.

The area around Kalgoorlie is undulating plains on granite, which have areas of calcareous loamy earths with red loamy earths, red deep loamy duplexes and red shallow loamy duplexes. In some town gardens, the soil cover over rock is shallow and can have a limiting effect on root development.

Some characteristics of Goldfields soil

Soil type Becomes non-wettable  Water holding capacity Nutrient holding capacity Benefits from organic matter Benefits from soil amendments
Sand  Very commonly Poor Poor Greatly Greatly
Sandy loam  Occasionally Medium Medium Greatly Some
Clay Very rarely Good Medium Greatly A little
Rocky or stony soils  Occasionally Medium Medium Greatly A little
Potting mix Very commonly  Good  Good N/A A little 


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