A cheat sheet to composting


According to the International Compost Awareness Week Australia (ICAW Australia), as much as 50 per cent of the rubbish Australians throw away could be put to better use in our gardens and farms by composting. That’s right! We could be saving up to 50 per cent of our waste from landfill AND getting nutrient rich fertilisers for our backyards in the process.

What are the benefits of composting?

  • Save waste from landfill – as much as 50 per cent of the rubbish Australians dispose of could be composted instead, leading to lower greenhouse gas emissions produced in landfill. Currently, 3 per cent of Australia’s total greenhouse gas emissions are estimated to be produced by “organically-active material buried ‘anaerobically’ (without air) in landfills”, according to ICAW Australia, “which has 25 times the global warming potential of carbon dioxide)”.
  • Create quality fertiliser and mulch for our gardens and farms. Compost is nutrient rich, full of all the good stuff that helps soil and plants thrive. 
  • Compost has a high water holding capacity, meaning it can retain far more water so you don’t have to irrigate as often! 
  • Compost fertilisers reduce the need for chemical fertilisers, meaning less pollutants and healthier plants – ideal for organic and urban farming. 
  • Compost products can also be used to create bio-filters to help clean up degraded land, such as areas around mines, and waterways that flow into the ocean.

To compost or not to compost, that is the question

There is a lot of noise around what you can and can’t compost. For example, we’re heard many times that you shouldn’t put onions or citrus in your compost. This is not true! So let’s set the record straight.

Following is advice sourced from Costa Georgiadis of ABC’s Gardening Australia. We know it there are conflicting views on this, so please feel free to add your views in the comments section!

Add these to your compost

Vegetable and fruit scraps, vegetable oil, prunings and lawn clippings, tea bags and coffee, grounds, vacuum dust, shredded paper and cardboard, used potting mix, egg shells, flowers.

On onions, citrus and other contentious items, Costa says there’s not much we should be afraid of.

The trick is balance

“The odd mandarin peel or the odd lemon in there, a good thriving compost will manage that no problem,” he told the ABC.

“But if you’re juicing oranges five or six days a week for three or four family members, that can overload a compost.”

The trick is balance. And if you’re worried, chop up any citrus peel and onion skin before they go in, and crush your eggshells to help them break down better.

Do NOT add these

Meat and bones, dairy products, diseased plants, metals, plastic and glass, animal manures, fat, magazines, large branches, weeds that have seeds or underground stems, sawdust from treated timber, pet droppings, synthetic chemicals.

How to create the classic cone shaped compost

According to The ABC’s Gardening Australia, setting up a cone shaped compost bin is pretty simple. 

You’ll need:

  • A compost bin
  • Some coarse, dry materials (such as sticks) to help with air circulation
  • Some green material (such as garden clippings, grass clippings, vegie scraps, green leaves)
  • Some brown material (such as moistened cardboard, egg containers, shredded paper (not glossy paper), straw, hay, sugarcane mulch, dry leaves)
  • A pitchfork or other tool to churn the compost


The process:

  • Bury the base of the compost bin in a shady spot in your yard
  • Add a layer of coarse, dry material
  • Add a layer of green material
  • Add a layer of brown material
  • Alternate layers of green and brown material – aiming for two parts brown to one part green
  • Turn once a week with your pitchfork 
If you don't have the space for your own backyard compost bin, try getting in touch with your local community garden

A few alternatives

Not everyone has the space in their yards for a cone shaped compost. If this is the case for you, try looking around your area for your closest community garden. They will usually have a composting facility and should welcome your donation of organic scraps. 

Otherwise, there are a number of smaller and indoor composting products available online. Have a search around for one that suits you.

If your restaurant or catering service creates a large quantity of food waste, Greenlisters Enrich360 may be able to help. They can supply you with a machine that macerates, heats and dehydrates food scraps into a pleasant smelling and dramatically condensed compost precursor that they then collect weekly and turn into fertiliser.