If — like me — your last experience with composting was making a worm farm back in school, it’s hard to know where to start. Even more so if you live in the inner-city, where limitations like a lack of space or concerns about the possible smells make setting up a compost feel out of reach.
But cook and author Alice Zaslavsky, who composts her family’s food scraps from an apartment in Melbourne’s CBD, says city dwellers don’t have to miss out on the satisfaction and ‘sustainability smugness’ that composting brings. It’s just about finding the system that works for you.
How does composting work?
Gardening extraordinaire and Sustainable Living diploma graduate Connie Cao says maintaining a compost is easier than you think. ‘It’s just about collecting organic matter [food scraps, grass clippings and plant cuttings] and dry matter [cardboard, wood chips, straw, shredded paper, newspaper, dried leaves, dried lawn clippings, small branches and sticks] and putting them into the bin in a balanced way.’
Then the compost accelerates the natural break down of this waste using air, heat, microbes, insects and other beneficial organisms that turn it into ‘extremely nourishing organic matter for your garden’.
Why should I start a compost?
The obvious benefit is that composts send significantly less waste to landfill. When organic waste is sent to landfill rather than recycled, it creates greenhouse emissions.
‘We went from emptying a bin bag per night — especially when I’m testing recipes — down to one bin bag a week,’ Alice says. ‘I believe that you can’t love food without recognising how much of it goes to waste as scraps. Composting does force you to rethink some things, like “does this have to go in the bin, or can it go in the scrap bag?” And from a cost-of-living perspective, it’s going to save you money because if you have a veggie patch or garden, you’re making your own [fertiliser].’
She says it’s a great way to teach kids about the importance of the food cycle, gardening and the environment! You can even get them involved by giving them tasks like tearing up paper, egg cartons and grocer boxes for dry matter.
Plus, Connie says compost is the ‘ultimate ingredient to creating lush, loamy, soils for growing plants’, and processing your own compost at home takes you one step closer towards a zero-waste lifestyle. ‘Our first composting system was subsidised by the council,’ she says. Make sure to check if your local council offers rebates, as you might even be able to set-up one for free.
What are the different methods of composting?
Electrical composts: As a cook and food writer who produces more food waste than the average household due, Alice has been using a (now discontinued) electrical kitchen composter called the Closed Loop CLOe for years. ‘We put all our scraps in, and it sits on the balcony and breaks down everything,’ she says.
Electrical composts are as simple as that. You put in some organic matter along with some brown matter, press a button and the machine does the rest, using high heat to desiccate the food and grind it into granules.
Depending on the machine, the composting cycle can take anywhere from a few hours to a few days before you can retrieve the dehydrated product. They’re often smaller in size, able to be stored under the sink, and are relatively odour-free, which makes them great for apartments.
Compost bins: Compost bins work in the same way, but without the electrical component. They tend to be a little larger in size and take an average of a few months for the compost to mature depending on your climate. There’s plenty of guides online on how you can create a DIY set-up, and they’re a great way to compost large quantities. But similar options like a freestanding, compost tumbler (which you spin to help speed up the process) or Bokashi bins (a contained bucket that ferments a compost liquid) are great alternatives for those with less space.
The Compost Depot co-founder Kirsteen Macleod says ‘anyone can have a worm farm or Bokashi bin, they don’t take up much space, can be kept in your laundry or kitchen and are easy to set up’. She uses a mix of systems, and estimates that it only takes her about 5-10 minutes every week to maintain the composts!
Worm farms: Last but not least, this kind of compost uses worms as the main source to break down the organic matter. Connie explains they require special composting worms (often tiger worms or red wrigglers) who are able to digest their body weight in food scraps every day, living inside the dry matter of your bin.
‘The good stuff you get from worm farms is called worm castings. This is what the worms excrete after they have digested and processed the food scraps in the worm farm, and can be used as an extremely nutritious “fertiliser” for your soil,’ she adds.
What goes into my compost?
There are two broad categories of what you should put in your compost bin; green matter and brown matter.
Green matter is also referred to as organic waste or nitrogen matter, and encompasses all your food scraps (or materials that are green and moist, i.e. grass clippings, plant cuttings and weeds).
Brown matter, also referred to as carbon matter, which is anything dried (cardboard, wood chips, straw, shredded paper, newspaper, dried leaves).
Connie advises putting both brown and green matter into your bin in a balanced way is crucial to ensuring you’re composting correctly. ‘You want to aim for 1:1 ratio in terms of the weight of nitrogen vs carbon matter,’ she says. ‘You can evaluate the balance of ingredients in your bin by simply observing the moisture level. If it’s too wet or smelly, simply add more carbon mater. If it’s too dry, simply add more nitrogen matter.’
What can’t I put in my compost?
While different systems can break down different food and garden scraps, these are the general items that don’t belong in your compost if you want to keep it happy:
– Meat and fish scraps
– Dairy, fats and oils
– Baked goods
– Plants or wood treated with pesticides or preservatives
– Diseased plants
– Charcoal ash
– Pet waste
Are there any downsides? What do I need to look out for when setting up my compost?
If you’re concerned about the smell, the good news is a ‘healthy’ compost is relatively smell-free, simply aim for the 1:1 ratio of green (nitrogen) and brown (carbon) matter.
Connie suggests, ‘With nitrogen matter, a small food scraps caddy or tub on your kitchen bench will easily do the job. You can line it with a compostable bag if you want to keep things neat however that’s entirely not necessary. If you’re worried about the juices getting everywhere, you can also line it with newspaper or paper towel at the bottom as well to soak up the juices.’
Even if you don’t have a garden to scatter the compost waste, team up with a friend or family member whose backyard could use the nutrients. There’s also the ShareWaste app, which connects people looking to donate their organic waste to other locals in the area — Kristeen describes it as ‘a Tinder for compost’! Or, find a community drop-off point like ones run by The Compost Depot.
I’m not ready to start a compost, what else can I do instead?
If none of those options work for you, you can always just put your food waste into the new Food Organics and Garden Organics (FOGO) bins with the green lids that are being rolled out across certain council areas. That way, councils can at still save the food scraps from going to landfill, processing them into compost in their own facilities without you having to do a thing!