What Is Composting? Nature’s Recycling

Ever wondered about the remarkable process that turns kitchen scraps, garden waste and other organic materials into a valuable resource for your garden?

It’s called composting – like nature’s version of recycling, it transfers organic waste into nutrient-rich ‘black gold.’ This process can divert waste from landfill, capture carbon and improve the health of soil, plants and the planet at large.

So, let’s dig deep and answer a common question: what is composting?

Composting Meaning

By definition, composting is the natural recycling and decomposing of organic matter (which is anything that was recently living). This includes leaves, garden waste, food scraps, paper and even compostable packaging.

Organic waste is broken down by living microorganisms such as bacteria and fungi, which all do their thing and turn it into simpler organic and inorganic compounds.

In nature, the process of natural recycling takes time. Composting is a way of speeding up this process by creating the ideal conditions (like temperate, moisture and aeration) for decomposition.

The end result looks like dirt, however, it’s a nutrient-rich fertiliser that can enrich your soil and plants.

So, What Is Compost?

If composting is the process of organic recycling, then compost is the final product – a soil-like material with a crumbly, smooth texture.

Compost is a combination of water, brown materials (like leaves, twigs and branches) and green materials (like grass, fruit and veggies). It’s often called ‘black gold’ because the valuable nutrients in compost can support soil, plants and increase agricultural yields.

How Does Compost Work?

Even though you can’t see them, most of the hard work in compost is done by microorganisms like bacteria, fungi and actinomycetes.

In simple terms, microorganisms eat the organic waste and then excrete it as ‘simpler parts’.

There are generally three phases of aerobic composting (composting techniques that involve the help of oxygen-loving microorganisms).

Mesophilic Phase
During this phase, mesophilic (moderate temperature) microorganisms begin breaking down organic materials.

Thermophilic Phase
During this phase, the compost pile heats up thanks to the activity of thermophilic (heat-loving) microorganisms. These high temperatures can help break down tougher materials.

Maturation Phase
Once the organic materials have broken down, the compost pile can cool down and enter the curing phase. Beneficial microorganisms still work, just at lower temperatures.

The result is a mature, dark and crumbling compost with an earthy smell.

Why Should You Compost?

There are so many reasons to compost. It’s turning what would otherwise be waste into a nutrient-rich, plant-loving resource. Compost can create a nutrient-rich fertiliser, promote healthy soil and plants, conserve water, prevent soil erosion, restore habitats and reduce carbon emissions associated with sending food to landfill. While it may seem overwhelming to get started, composting is actually incredibly simple. Learn more about How To Compost at Home and The Benefits of Composting.

What Can You Compost At Home?

Organic material is anything that was recently living.

Here’s a quick guide to what you can and can’t compost.

What Can You Compost?

Fruit
Vegetables
Leaves
Grass trimmings
Eggshells
Tea bags (provided they’re not plastic)
Hair
Coffee grounds
Paper
Wood chips
Cardboard
Certified home compostable packaging, like brown paper lunch bags, coffee cups, bowls and cutlery (always look for the correct home compostable certification – learn more about the certification here)

What Can’t You Compost?

Fossil-based plastic
String
Aluminium foil
Dryer and washing machine lint
Dust from the vacuum cleaner
Large twigs and branches
Pet droppings
Wax paper and cardboard
Animal and meat products*

*Animal and meat products can be composted, but it’s not always recommended or you should limit the amount you compost as it may attract pests.

Learn more: What Goes in a Compost Bin?

What Is Compost Used For?

Once you have your finished product, nutrient-rich compost, you can add it back to the soil. It’s great for returning nutrients to depleted soil.

The best thing about compost is it can be used at a range of different scales – from your small backyard veggie patch all the way to large agricultural systems, potentially reducing the need for chemical fertilisers and pesticides.