The Benefits of Applying Good Compost: A Guide to Composting Methods
Composting is one of the most effective ways to enhance soil health, reduce waste, and improve plant growth. Whether you're a home gardener or a commercial grower, without good quality compost your plants aren’t thriving like they could be. Yep, we said it. Compost enriches the soil, promotes healthy plant development, and supports sustainable gardening practices. In Australia, it's estimated that organic waste makes up a significant portion of household waste, much of which ends up in landfills. Home composting can help reduce this, and government initiatives have been launched to encourage more households to compost. In this guide, we’ll explore the various composting methods and help you decide whether making your own compost or buying it is best for you.
What Makes Good Compost Good? A Guide to Identifying Quality Compost
If you’re new to the world of composting, firstly – welcome. Secondly, you might be wondering to yourself… ‘how do I know if the compost I’m buying is any good?’. Well, you’ve come to the right place. Because it should be known – not all compost is created equal.
High-quality compost is a growers best friend; it enriches soil, boosts plant growth, and improves overall soil health. But what exactly makes compost good? Here’s what to look for when identifying high-quality compost:
It’s got a balanced composition
Just like us humans can’t survive off sugar and snack foods alone – our crops need the right balance of carbon-rich materials ("browns" like dead leaves and straw) and nitrogen-rich materials ("greens" like kitchen scraps and grass clippings). A well-balanced compost mix provides a nutrient-rich environment that fosters plant growth.
What to look for: Compost that contains a blend of organic materials, without too much of one type (e.g., all green or all brown material).
It smells like, well…compost!
One of the best indicators of good compost is the smell. Quality compost has a rich, earthy aroma, similar to the smell of fresh soil after rainfall.
What to avoid: Compost that smells sour, rotten, or has a strong ammonia scent, which could indicate incomplete decomposition or the presence of harmful bacteria.
Dark, Crumbly Texture
Good compost has a dark, uniform colour and a crumbly texture, similar to that of rich garden soil. This indicates that the organic matter has fully decomposed, leaving behind humus—organic material that is ready to be used in the garden.
What to avoid: Compost that is chunky, with visible pieces of undecomposed material like large twigs or food scraps, indicating that it hasn't fully broken down.
Moisture Content
Quality compost should feel like a damp sponge—not too wet and not too dry. The right moisture level is essential for composting microbes to thrive.
What to look for: Compost that is moist to the touch but not waterlogged. It should not release water when squeezed, and it shouldn't feel dusty or overly dry.
pH Level
The pH of compost should be neutral to slightly acidic, with a pH range of about 6 to 7. This ensures that the compost is not too acidic or too alkaline, which can harm plants.
What to look for: Many commercial composts list the pH on the label, but if you're making your own, a soil test kit can help you measure the pH.
Free from Contaminants
Good compost should be free from harmful chemicals, pesticides, herbicides, or weed seeds that can damage your garden. Organic compost, in particular, should not contain any synthetic additives.
What to avoid: Compost with plastic fragments, glass, or any other non-organic material. Additionally, be wary of composts that contain treated grass clippings or materials exposed to herbicides, as they can harm your plants.
Contains Beneficial Microorganisms
Quality compost is teeming with life—specifically beneficial microbes such as bacteria and fungi that help break down organic matter and release nutrients into the soil. This microbial activity is crucial for maintaining healthy soil and supporting plant growth.
What to look for: Although microbes aren't visible to the naked eye, good compost that has been well-maintained and aerated will naturally contain these beneficial organisms.
The Benefits of Good Compost
Applying high-quality compost to your garden or farm offers numerous advantages:
Builds Organic Matter: Compost enhances soil structure by increasing organic matter, which leads to better aeration, water retention, and root growth.
Improves Soil Biology: Compost introduces beneficial microorganisms that help break down nutrients, making them more accessible to plants. These microbes contribute to a healthier, more fertile soil ecosystem.
Suppresses Weeds: A well-applied layer of compost can help suppress weed growth by blocking sunlight and smothering young weeds, making your garden easier to maintain.
Retains Soil Moisture: Compost acts like a sponge, holding moisture in the soil and reducing the need for frequent watering. This is especially beneficial in hot or dry climates.
Key Composting Methods
So we’ve convinced you that composting is worth it, for the sake of the health and happiness of your crops. If you’re looking for a sustainable, self-sufficient, DIY option, there are several methods of composting, each with its own benefits and challenges. These methods differ in the level of effort and time they require, but all provide valuable compost that helps improve soil health, retain moisture, and feed plants naturally. Here’s a breakdown of four popular composting methods:
Cold Composting
Cold composting is the easiest, low-maintenance way to compost. Think: those good ol’ compost bins you probably had in your backyard as a kid. Simply fill it up with your organic waste—such as vegetable scraps, leaves, and grass clippings—and let it decompose over time. It takes about 6 to 12 months for the materials to break down naturally thanks to the natural activity of microbes, worms and insects, but the process requires little effort as it doesn’t require turning or monitoring.
What’s in it?
Green Materials: Add your kitchen scraps such as fruit peels, veggie scraps, grass clippings, coffee grounds, egg shells and more. These will give your compost nitrogen.
Brown Materials: Dry leaves, straw, wood chips, and shredded paper. These are all rich sources of carbon for your compost.
Pros & Cons
Pros: Low maintenance, no turning required.
Cons: Takes longer to break down, can develop an odour and may attract pests if not covered properly.
Hot Composting
Hot composting is a faster, more intensive method that can produce compost in as little as 1 to 3 months, as it accelerates the decomposition process. The internal temperature should reach and be maintained at between 55°C to 65°C, which also kills pathogens and weed seeds. This is achieved by frequently turning the pile to aerate it, and maintaining a good balance of nitrogen-rich and carbon-rich materials.
What’s in it?
Green materials: Grass clippings, fresh vegetable peels, manure (from herbivores), and coffee grounds for nitrogen.
Brown materials: Dead leaves, sawdust, straw, and cardboard for carbon.
Water: Proper moisture levels are essential— the pile should feel like a damp sponge.
Pros and Cons:
Pros: Quick decomposition, kills weeds and pathogens.
Cons: Requires more effort to manage (turning, moisture control), needs more space and if temperature is not regularly checked the compost piles do pose a fire-risk (as they can become too hot and catch alight).
In-bed Composting
In-bed composting, also known as trench or sheet composting, involves burying organic waste materials directly into garden beds, where they decompose in place. This method enriches the soil, feeding the plants directly, without needing to build a separate compost heap or bin. All that’s required here is a shovel and some patience as this method is relatively low-effort.
What’s in it?
Green materials: Food scraps, plant prunings, coffee grounds, and grass clippings.
Brown materials: Dry leaves, straw, and shredded paper for carbon.
Mulch: A layer of mulch can be added on top to help retain moisture and aid in the decomposition process.
Pros and Cons
Pros: No need for a separate compost bin, feeds plants directly.
Cons: Slow process, requires patience, can disrupt plant roots if not managed carefully.
Worm Composting (Subpod)
Worm composting, or vermiculture, uses worms to break down organic matter into rich compost known as worm castings. Worm composting can be in an above ground dedicated ‘worm farm’, or in an inground composting bin such as the Subpod system. The Subpod integrates your compost directly into garden beds, creating an efficient and odourless way to recycle food scraps and generate nutrient-rich fertiliser.
How it works:
Organic waste is placed inside the Subpod unit, where composting worms (typically red wigglers) consume and process the material. The worms digest the waste, producing castings (a natural fertiliser) and compost tea (a nutrient-rich liquid) that directly nourishes the surrounding plants. The system is partially buried in the soil, allowing worms to move freely between the compost and the garden bed.
What’s in it?
Worm Food (Green materials): Fruit and vegetable scraps, coffee grounds, crushed eggshells, and tea bags. These are nitrogen-rich and serve as food for the worms.
Brown materials: Shredded newspaper, cardboard, dry leaves, and straw, which help create a balanced environment for worm digestion by providing carbon.
Worms: It’s important to kickstart your compost with a healthy dose of live worms, which will be all too happy to get munching on your compost.
Note: It’s important to avoid meat, dairy, oils, and citrus as they can harm worms and disrupt the composting process.
Pros and Cons:
Pros: Produces high-quality compost and compost tea, ideal for small spaces, fast decomposition.
Cons: Requires ongoing worm care, can't compost all food waste (e.g., meat, dairy).
Making Your Own Compost vs. Buying Compost
When deciding between making your own compost and buying it, it’s important to consider factors such as time, cost, and convenience.
Making Your Own Compost
Pros:
Cost-effective: You can use kitchen scraps, leaves, and yard waste, cutting down on household waste and saving money.
Control: You control what goes into the compost, ensuring it's organic and free from harmful chemicals.
Sustainability: Homemade compost reduces your environmental footprint by recycling waste.
Cons:
Time-consuming: Composting can take months to produce usable compost.
Space: Requires space for a compost bin or pile, which might not be feasible for all households.
Maintenance: Regular turning, monitoring moisture levels, and managing odours can be labour-intensive.
Buying Compost
Pros:
Convenient: Pre-made compost is ready to use immediately.
High-quality options: Many store-bought composts are balanced for nutrients and free from contaminants.
Time-saving: Ideal for those who need compost quickly without the effort of making it themselves.
Cons:
Expensive: Continually purchasing compost can be costly, especially for larger gardens or farms.
Less control: You may not know exactly what went into the compost, and some products might contain non-organic materials.
Environmental impact: Commercial compost production and transportation may contribute to a higher carbon footprint.
Composting is a powerful tool for any gardener or eco-conscious individual. Whether you choose to make your own compost or buy it, adding compost to your soil can lead to healthier plants, reduced waste, and a more sustainable lifestyle. Explore the composting method that suits your lifestyle and garden needs, and start reaping the benefits of this natural soil enhancer.
