Key Takeaways
- Compost improves soil structure, boosts nutrients, and helps plants grow strong.
- The right amount of compost depends on your garden size and soil type.
- Buying compost in bulk instead of bags can save money for large gardens or landscaping projects.
- Organic compost benefits include better water retention, fewer weeds, and a healthier environment.
- Using quality compost from trusted suppliers like SA Landscape Supplies ensures long-term soil health.
What Is Compost and Why It Matters
Compost is nature’s way of recycling. It’s made from broken-down organic materials like leaves, grass clippings, and food scraps. When mixed into soil, compost improves its structure, adds nutrients, and supports beneficial microbes that keep plants healthy.
In short, compost turns waste into a valuable resource for your garden. Whether you’re growing vegetables, flowers, or lawn, compost helps create the perfect environment for roots to thrive.
According to the Australian Government’s Department of Climate Change, Energy, the Environment and Water, composting is one of the best ways to reduce landfill waste while enriching soil.

Why Compost Is So Important for Soil Health
1. Improves Soil Structure
Healthy soil should be crumbly, not compacted. Compost helps loosen clay soils and gives sandy soils more body. This creates better airflow and drainage, allowing roots to grow deeper and stronger.
2. Boosts Nutrient Content
Compost adds key nutrients like nitrogen, phosphorus, and potassium. These nutrients are released slowly, feeding plants over time instead of all at once like chemical fertiliszers do.
3. Encourages Microbial Activity
Good soil is alive. Compost introduces beneficial microorganisms that help break down organic matter and release nutrients. These microbes also protect plants from some soil-borne diseases.
4. Retains Water Better
Adding compost increases your soil’s water-holding capacity. This means less watering and stronger, more drought-resistant plants — a big win for Australian gardeners in dry regions like South Australia.
5. Reduces Waste
By composting food and garden waste, you’re helping reduce landfill volume and greenhouse gas emissions. It’s a small change with a big environmental payoff.
How Much Compost Do You Really Need?
Knowing how much compost to use depends on your project. Here’s a simple guide:
| Project Type | Compost Depth | Amount Needed (per m²) |
| Lawn Topdressing | 1–2 cm | 0.01–0.02 m³ |
| Vegetable Beds | 5–10 cm | 0.05–0.10 m³ |
| New Garden Beds | 10–15 cm | 0.10–0.15 m³ |
| Soil Improvement | 2–5 cm | 0.02–0.05 m³ |
Tip: For large gardens or landscaping jobs, buying compost in bulk instead of bagged compost from SA Landscape Supplies can be more cost-effective than purchasing smaller bags.
Types of Compost and Their Uses
1. Organic Compost
Made from natural materials, organic compost supports sustainable gardening. It’s rich in beneficial bacteria and nutrients. Organic compost benefits include improved soil fertility, reduced erosion, and stronger root systems https://salandscape.com.au/product/jeffries-organic-compost/.
2. Mushroom Compost
This type is made from the leftover substrate used in mushroom farming. It’s great for vegetable gardens but should be mixed with other soil types to balance pH levels https://salandscape.com.au/product/mushroom-compost/.
3. Green Waste Compost
Produced from recycled green materials like branches and leaves, it’s perfect for improving poor soils.
4. Animal Manure Compost
Aged manure (like cow or chicken) adds extra nitrogen, making it excellent for nutrient-hungry plants. Always make sure it’s well-composted before using.
The Benefits of Organic Compost
Using organic compost offers a wide range of benefits beyond healthy plants. Here’s why it’s worth choosing:
- Eco-Friendly: Reduces chemical fertilizer use and supports biodiversity.
- Improves Soil pH: Helps balance acidity and alkalinity.
- Less Erosion: Strengthens soil structure, preventing wash-away during heavy rain.
- Healthier Plants: Encourages disease resistance and strong root development.
- Saves Water: Better moisture retention means less watering.
The Queensland Government’s Department of Environment and Science highlights that composting also helps recycle organic waste safely and effectively.

How to Apply Compost the Right Way
Step 1: Measure Your Area
Use the table above to calculate how much compost you’ll need. For big spaces, consider ordering compost in bulk instead of in bags to save on delivery and handling.
Step 2: Prepare the Soil
Remove weeds, rocks, and debris. Loosen compacted soil with a rake or garden fork.
Step 3: Spread Evenly
Spread the compost evenly over the area using a shovel or wheelbarrow. Aim for a consistent layer based on your soil type and garden goal.
Step 4: Mix It In
Turn the compost into the top 10–20 cm of soil. Mixing ensures nutrients are evenly distributed and ready for plant roots.
Step 5: Water and Wait
Lightly water the soil after applying compost. This activates microbial activity and helps the compost settle.
How Compost Impacts Soil Over Time
Compost doesn’t just make your garden look good — it transforms it over time. Within a few months, you’ll notice improved soil texture and healthier plants. After a year or two, your soil will hold water better, resist compaction, and support long-term plant growth.
Regularly adding compost (once or twice a year) maintains this improvement and keeps your garden thriving.
Buying Compost in Bulk: When It Makes Sense
If you’re working on a big project, a compost in bulk is a smart investment. Here’s why:
- Cost Savings: Bulk buying reduces the price per cubic metre.
- Consistency: You’ll get the same compost quality across your entire garden.
- Convenience: Fewer trips and less packaging waste.
SA Landscape Supplies provides high-quality compost options perfect for landscapers, gardeners, and homeowners alike. Explore their full range at https://salandscape.com.au/shop/

Top 5 Signs Your Soil Needs Compost
Below is just some of the signs that your garden might need compost:
- Hard or compacted texture – water doesn’t soak in easily.
- Yellowing leaves – signs of nutrient deficiency.
- Poor plant growth – stunted roots or weak stems.
- Low earthworm activity – fewer worms mean poor soil life.
- Crusting surface – dry, cracked soil that doesn’t hold moisture.
If you notice any of these, it might be’s time to enrich your soil with compost.
Frequently Asked Questions
1. How often should I add compost to my garden?
Once or twice a year is ideal — usually in spring and autumn.
2. Can I use compost instead of fertilizer?
Yes, compost provides nutrients naturally, but for fast-growing plants, you can combine it with organic fertiliszer.
3. What’s the difference between compost and mulch?
Compost feeds the soil, while mulch mainly protects it from heat and weeds.
4. Is compost safe for all plants?
Most plants love compost, but avoid using fresh or unaged compost for sensitive seedlings.
5. How long does compost take to improve soil?
You’ll start seeing results within a few weeks, but full improvement can take several months.
6. Can I make compost at home?
Absolutely! Kitchen scraps, grass clippings, and dry leaves can all go into a home compost bin.
7. Can compost go bad?
Properly stored compost lasts for years, but if it smells rotten or sour, it may need aeration.
8. Should I mix compost with sand or soil?
Yes, mixing compost with garden soil improves structure and nutrient balance.
9. Is organic compost better?
Yes, organic compost benefits both your garden and the planet by avoiding chemicals and supporting soil life.
Conclusion: Healthier Soil Starts with Compost
Compost is the foundation of strong, healthy soil. Whether you’re starting a small veggie patch or revamping a large landscape, using the right amount of compost helps your plants thrive naturally.
For the best results, choose quality compost from SA Landscape Supplies. Explore their range, order a compost in bulk or compost in bags and start improving your soil today.
Visit SA Landscape Supplies to find the right compost blend for your garden.