Turn Sand into Soil

Gardening in Perth's sandy soils can be a huge challenge, as confirmed by a recent customer survey indicating it as one of the top frustrations for many of our customers. The sandy soils in Western Australia are ancient and lack nutrients and organic material, making them less than ideal for gardening. However, with the right strategies, you can transform your sandy soil into a fertile, productive garden.

Why is Sandy Soil so Challenging?

1. Lack of Water-Holding Ability

Particle Size - sand: Sand particles are large with smooth surfaces, resulting in a small surface area and limited water retention.
Particle Size - clay: Clay particles, on the other hand, are tiny with a large surface area, allowing them to hold three to six times more water than sand.
Micropores: Soil particles have micropores that fill with water. Sand has larger pores but fewer, making it unable to hold much water compared to clay.

2. Lack of Organic Material and Humus

Lack of Organic Matter: Perth's sandy soil contains less than 1% organic matter ("ideal" soil should have at least 5% for vegetable growing).
Importance of Humus: Organic matter decomposes into humus, a stable form that improves soil structure, water retention, and nutrient availability.
Organic Matter provides habitat for Microorganisms: Organic matter feeds soil microorganisms, which make nutrients available to plants. Humus acts like a sponge, holding water and nutrients.

3. Poor Soil Structure

Sand particles are too regular: A range of particle sizes creates a balanced soil structure, allowing for air and water pockets necessary for plant growth.
Challenges with Sand: Too many large particles result in excessive drainage, while too many small particles cause compaction. Ideal soil, or loam, has a mixture of particle sizes and mineral components - sand, clay & silt (which naturally comes with clay).

4. Cation Exchange Capacity (CEC)

Nutrient Retention: Clay and humus hold onto nutrients due to their electrical charge, making them available to plants as needed. Sandy soil lacks this capability, leading to nutrient leaching.
Cation Exchange: Similar to static electricity attracting hair to a balloon, nutrients in soil are attracted to clay and humus particles, allowing plants to access them slowly.

Turning Sand into Soil

Improving sandy soil requires multiple strategies and a bit of patience. Here are the key steps to enhance your soil:

1. Add Clay

There are two types of Clay available for home gardeners to use - Bentonite and Kaolinite

Bentonite Clay: Use calcium bentonite over sodium bentonite due to its beneficial properties (and lower salt content).
Application: Incorporate bentonite at 1-5% by weight. Start with 500g-1kg per square meter and adjust as needed. Use dry bentonite to avoid clumping.

Kaolinite Clay: Available as "Cassies Clay," also Certified Organic and Smart Watermark approved. Cassies Clay has a naturally low pH and is perfect for lowering pH in coastal gardens, as well as permanently improving soil structure and water holding ability.
Application: Apply at 5-15kg per square meter, depending on other soil improvement practices. Easier to incorporate into soil than bentonite.

Bentonite Vs. Kaolinite: Both types of clay have their place, with different pros and cons. Bentonite should be used at lower ratios (500gm - 2kg per square metre 1-5%), while kaolinite requires higher application rates (5-15kg per square meter 5-10%). Bentonite should be incorporated into dry soil (to prevent it sticking to itself), while kaolinite is easier to work with. Both clays are sourced within Western Australia.

Green Life Soil Co stocks both Bentonite & Kaolinite clay... as well as our own product:

Sand Remedy: Certified Organic product containing calcium bentonite and other beneficial minerals (including volcanic rock dust/trace elements), designed to enhance soil health as well as water holding - and endorsed by Smart Watermark and Waterwise.

With any clay, we recommend you start at a lower application and add more as required - particularly to established gardens where soil has been enhanced.
On plain/unimproved soil and before laying new turf work on higher application rates.
It is recommended to add clay to around 300mm depth (roughly spade depth), mixing in well.

2. Add Organic Matter

Sources: Animal manures, compost, straw, etc.
Benefits: Organic matter feeds soil microbes, improving soil structure, water retention, and nutrient availability.
Consistency: Regularly add organic matter to maintain soil health.
Try Biochar: Charlie Charcoal, our biochar product that enhances soil structure and nutrient retention, is a stable, long-term solution for soil improvement. Biochar acts like humus by creating a habitat for soil microbes without being consumed, holding water and nutrients effectively.
Persistence: Organic material breaks down over time, so continual addition is necessary. However, over 3-5 years, you will need to add less as humus levels build up. Organic matter is quickly used up in sandy soils, with 70% decomposing in the first year and 50% of the remaining material in the second year.

Financial and Personal Benefits

Improving sandy soil might require some investment, but the benefits of a healthy garden, including fitness, outdoor activity, and homegrown food, are invaluable. Remember, there's no quick fix, but the rewards are worth the effort. Adding clay and biochar are both permanent ingredients that stay in your soil.

Final Thoughts

Gardening in South Western Australia's sandy soils is challenging but achievable with the right approach. Transforming your sandy soil into a productive garden requires time, patience, and the right techniques.

Get Expert Help

Need help improving your sandy soil? Visit our store for personalized advice and solutions tailored to your garden's needs. Our experts are ready to assist you in creating a thriving garden. Enjoy the journey, and let us help you achieve your gardening dreams!

Improving sandy soil involves a blend of strategies, including adding clay and organic matter, to create a fertile, thriving garden environment. For tailored advice and expert help, visit our Middle Swan store and let us assist you on your gardening journey.

Bring in a sample of your soil (approx. 1-5L) for us to do a test with clay to show you the difference it will make to your soil structure immediately.

Products for Turning Sand into Soil

There are several products from our product range that are perfect for changing Sand into Soil in Perth. If you need help or advice to choose what’s best for you – please contact us today!