Improving your soil
Good soil is the foundation of a healthy waterwise garden, and the healthier your soil is, the more drought resistant your plants will be.
Mulch is like sunscreen for your soil
Applying mulch to your garden can greatly reduce evaporation loss, improve the soil, reduce plant stress and weed growth, as well as improve the appearance of your garden.
Here are some handy tips for mulching your garden:
- Apply between 5–10cm of good waterwise mulch
- Choose a chunky coarse mulch
- Choose products displaying the Waterwise and Smart Approved WaterMark symbols
For mulching techniques and tips watch this video:
Read a transcript of this video
Great gardeners improve the soil every time they dig
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:
- 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.
- 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 clay:
Read a transcript of this video
Wetting agents
Apply a soil improver with a wetting agent at the start of winter rains, in early summer and as recommended by the manufacturer. Always water in wetting agents until they foam. This means they are activated and doing their job.
Watch this video about improving your soil through the use of wetting agents:
Read a transcript of this video
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.
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 |
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 |
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 |
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 |
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 |
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