I started composting three years ago after reading approximately forty articles about how easy it was. It isn’t easy — at least not at first. My first compost bin turned into a slimy, stinking mess that attracted flies and produced nothing useful for about six months.

But once I figured out what I was doing wrong, composting became genuinely straightforward. The problem with most composting guides is that they either oversimplify (“just add scraps!”) or overcomplicate (“maintain a precise carbon-to-nitrogen ratio of 25:1”). Here’s what actually matters for a suburban Australian backyard.

The Only Science You Need to Know

Composting is controlled decomposition. Microorganisms (bacteria, fungi) break down organic material into humus — the dark, crumbly, earthy-smelling stuff that makes soil better. Your job is to give those microorganisms what they need: carbon, nitrogen, moisture, and air.

Carbon comes from “brown” materials: dried leaves, shredded paper, cardboard, straw, sawdust, dead plant material. Carbon provides energy for microorganisms.

Nitrogen comes from “green” materials: kitchen scraps, fresh grass clippings, green plant trimmings, coffee grounds (technically brown in colour but “green” in composting terms). Nitrogen provides protein for microorganisms.

The ideal ratio is roughly 3 parts brown to 1 part green by volume. Don’t stress about getting it exact. If your compost is too wet and smelly, add more brown. If it’s too dry and nothing’s happening, add more green.

Choosing a System

There are three main composting approaches for suburban backyards. Here’s an honest comparison.

Open Compost Bin or Bay

The classic approach. A bin (typically 200-400 litres) or a bay made from timber pallets, sitting directly on soil. This is what most councils subsidise — check with your local council, because many Australian councils offer compost bins at discounted prices. The Australian Government’s composting guide has links to state and council programs.

Pros: Cheap ($30-80 for a subsidised bin), simple, handles large volumes, worms and beneficial insects naturally colonise from the soil below.

Cons: Slower (3-6 months to produce finished compost), can attract pests if not managed properly, needs a bit of garden space.

Best for: Houses with backyards who produce moderate kitchen waste and have garden waste to add.

Tumbler Composter

An enclosed drum on a frame that you rotate to mix the contents. Prices range from $100 to $350.

Pros: Faster decomposition (6-10 weeks if managed well), pest-resistant due to enclosed design, no digging or turning with a fork.

Cons: Limited capacity, can overheat in Australian summer sun (killing beneficial organisms), doesn’t allow worm colonisation, and the “tumble daily” instruction gets tedious after the first week.

Best for: Smaller gardens, people who want faster results, units with a balcony (some tumblers are compact enough).

Worm Farm

Not technically composting — it’s vermicomposting. Worms (usually red wrigglers or tiger worms) eat your food scraps and produce worm castings (extremely good fertiliser) and worm tea (liquid fertiliser).

Pros: Works in small spaces (balcony, garage, laundry), produces the highest-quality soil amendment, great for apartment dwellers, and worms are entertaining if you’re into that sort of thing.

Cons: Worms are fussy eaters (no citrus, no onions, no meat, limited bread), limited capacity (a standard worm farm handles about 2-3 kg of scraps per week for a household of 2), worms die in temperatures above 35 degrees (they need shade in summer), and you need to buy the worms initially ($40-60 for a starter colony).

Best for: Apartments, small households, people who want premium garden fertiliser.

I use an open compost bin for bulk material (garden waste, cardboard, larger quantities of kitchen scraps) and a small worm farm for fine kitchen scraps. The two-system approach covers most household organic waste.

What Goes In and What Doesn’t

Compost Bin — Yes:

• Fruit and vegetable scraps (including peelings, cores, stalks)
• Coffee grounds and tea bags (remove staples from tea bags)
• Eggshells (crush them first — they break down slowly otherwise)
• Shredded paper and cardboard (remove tape and plastic windows from envelopes)
• Dried leaves, grass clippings (let grass dry for a day before adding)
• Garden prunings (chopped small)
• Straw, hay, sawdust from untreated timber

Compost Bin — No:

• Meat, fish, bones, dairy (attracts rats and foxes, creates smell)
• Diseased plants (the compost may not get hot enough to kill pathogens)
• Weeds with seeds (unless your compost reaches 55+ degrees consistently)
• Pet waste from dogs and cats (contains parasites)
• Treated timber sawdust (chemicals persist)
• Glossy magazines (the coating contains plastics)

Worm Farm — Yes:

• Fruit and vegetable scraps (cut small)
• Coffee grounds
• Soaked cardboard and newspaper (bedding material)
• Crushed eggshells

Worm Farm — No:

• Citrus, onion, garlic (too acidic, worms avoid them)
• Meat, dairy
• Bread in large quantities (attracts vinegar flies)
• Spicy foods
• Anything salty

The Mistakes I Made (So You Don’t Have To)

Mistake 1: Too much green, not enough brown. My first bin was almost entirely kitchen scraps with maybe a handful of leaves thrown in occasionally. Result: a wet, anaerobic, stinking pile. The fix was simple — I started keeping a bag of dried leaves next to the compost bin and adding a generous handful every time I added scraps.

Mistake 2: Not chopping things up. Whole broccoli stalks and intact avocado skins take months to decompose. Chop everything into pieces no bigger than 5cm. Smaller surface area means faster breakdown.

Mistake 3: Ignoring moisture. Compost should be roughly as moist as a wrung-out sponge. In an Australian summer, open bins dry out quickly. I water mine lightly once a week during hot, dry periods. In winter or during rain, I add extra cardboard to absorb excess moisture.

Mistake 4: Never turning it. You don’t need to turn compost obsessively, but aerating it every 2-3 weeks speeds things up dramatically. I use a compost aerator (a metal rod with fold-out wings, about $25) rather than a garden fork. It’s much quicker and doesn’t require removing the bin.

Mistake 5: Expecting instant results. Hot composting (reaching temperatures of 55-65 degrees) can produce finished compost in 6-8 weeks. Cold composting (what most backyard bins do) takes 3-6 months or longer. I spent my first two months thinking something was wrong because nothing was “happening.” Things were happening — just slowly.

How to Know When It’s Ready

Finished compost is dark brown to black, crumbly, and smells like forest floor — earthy and clean, not rotting or sour. You shouldn’t be able to identify any of the original inputs (except maybe eggshells, which take ages).

If you’re not sure, do the bag test: put a handful in a sealed plastic bag for 24 hours. If the bag puffs up (gas production), it’s not finished. If it stays flat and doesn’t smell bad when opened, it’s ready.

What to Do With Finished Compost

Mix it into garden beds before planting, spread it around established plants as a top dressing (keep it away from stems), use it as a seed-raising mix component, or add it to potting mix at a ratio of about 1 part compost to 3 parts potting mix.

Finished compost improves soil structure, water retention, and provides slow-release nutrients. It’s not a substitute for specific fertilisers (if your citrus needs iron, compost won’t fix that), but it’s the single best thing you can do for general soil health.

The Environmental Bit

About 40% of what Australians send to landfill is organic waste. In landfill, organic waste decomposes anaerobically and produces methane — a greenhouse gas roughly 28 times more potent than CO2 over a 100-year period. Composting at home diverts that waste and produces something useful instead.

It’s not going to save the planet on its own. But it’s one of those things where individual action genuinely adds up, and you get better tomatoes out of it. Hard to argue with that.