What Can You Compost? A Complete Australian Guide
One of the most common questions from people getting started with composting is: “What can actually go in?” The short answer is: more than you’d think. The longer answer depends on which composting method you’re using and what results you’re after.
This guide covers every major category of compostable material, with notes on quantities, preparation, and which composting systems suit each type.
@lottiedalziel It’s all about the balance 🐛 #compost #composting #gogreen #sustainability #sustainableliving #gogreen #ecofriendly ♬ original sound - Lottie Dalziel🌏Sustainability
The green-brown framework
Before diving into the full list, it helps to understand that compostable materials fall into two categories:
- Greens (nitrogen-rich): Wet, fresh, or recently living materials. Provide nitrogen and moisture. Examples: food scraps, lawn clippings, coffee grounds.
- Browns (carbon-rich): Dry, dead, or wood-derived materials. Provide carbon and structure. Examples: cardboard, dry leaves, paper, wood chips.
A healthy compost pile needs both. The ideal ratio is roughly 3 parts brown to 1 part green by volume. Most beginners add too many greens and not enough browns — keep a pile of torn cardboard near your bin as a ready supply.
Food scraps: what’s in and what’s out
| Food item | Standard bin | Tumbler | Worm farm | Bokashi | Notes |
|---|---|---|---|---|---|
| Fruit & vegetable scraps | Yes | Yes | Yes | Yes | Core composting material |
| Coffee grounds | Yes | Yes | Yes | Yes | Worms love them; don’t overdo it |
| Tea leaves | Yes | Yes | Yes | Yes | Remove staples from tea bags |
| Eggshells | Yes | Yes | Crushed only | Yes | Crush before adding; adds calcium |
| Bread and grains | Caution | Yes | Small amounts | Yes | Attracts pests in open bins |
| Cooked vegetables | Caution | Yes | Sparingly | Yes | Avoid oily cooked food in open bins |
| Meat and fish | No | Caution | No | Yes | Bokashi handles meat and fish well |
| Dairy products | No | Caution | No | Yes | Same as meat — Bokashi only |
| Citrus peel | Yes | Yes | Small amounts | Yes | Slows worm activity in large quantities |
| Onion and garlic | Yes | Yes | Small amounts | Yes | Worms dislike large quantities |
Garden and yard waste
- Lawn clippings (green) — excellent nitrogen source; add in thin layers to prevent matting
- Dry leaves (brown) — ideal carbon source; shred or crunch for faster breakdown
- Plant trimmings and weeds (before seeding) — chop into smaller pieces
- Spent potting mix — great for bulk; mix with greens
- Straw and hay (brown) — excellent bulking agent
- Wood chips and sawdust (untreated wood only) — very high carbon; use sparingly or pre-wet
Caution: garden waste to avoid
- Diseased plants (can spread disease through the pile and into your garden)
- Weeds that have set seed (seeds may survive if the pile doesn’t reach temperatures of 55+°C)
- Branches thicker than 1cm (too slow to break down; chip first or use a separate woody waste system)
- Invasive weeds like kikuyu, wandering dew, or couch grass (fragments can regrow in the pile)
Paper and cardboard
- Cardboard (uncoated, no glossy coating) — tear into pieces; excellent brown material
- Newspaper — shred or scrunch; modern newspaper inks are typically soy-based and safe
- Paper bags, paper towel, and cardboard egg cartons — excellent browns
- Cardboard toilet roll tubes and cereal boxes (remove any plastic bags inside)
Paper and cardboard to avoid
- Glossy magazines and coated paper (the coating prevents breakdown and may contain contaminants)
- Waxed cardboard (e.g. produce boxes — these have a wax coating that inhibits breakdown)
- Paper with heavy plastic laminate or foil printing
Other compostable materials
- Natural fibre textiles (100% cotton, wool, linen — cut into small pieces; remove buttons and zips)
- Hair and nail clippings (human or pet hair — takes a while but does break down)
- Wood ash (in small amounts; raises pH so use sparingly)
- Compostable packaging labelled AS 4736 (requires high-temperature pile or industrial composting)
@lottiedalziel Some of these might shock you… but all of them can go in your compost bin to get turned into healthy fertiliser for your garden! 🌱 If you don’t have the space for your own compost bin, check out tools like Make Soil or the Peels app 🪱 #compost #composting #howtocompost #zerowaste #environmentaleducation #sustainableliving ♬ Walking Around - Instrumental Version - Eldar Kedem
Frequently Asked Questions
Can you compost orange peels?
Yes. Citrus peel breaks down more slowly than other fruit scraps and can slow worm activity in large quantities, but it’s perfectly fine in standard outdoor compost bins in moderation.
Can you compost paper towels?
Yes — unbleached paper towel is ideal. Even a bleached paper towel is generally fine in outdoor compost bins. Avoid paper towels used to clean up harsh chemicals.
Can you compost cooked food?
Cooked vegetables without oil are fine in most systems. Cooked food with oil, meat, dairy, or strong flavours is best handled in a Bokashi system or a sealed tumbler compost bin.
Can you compost teabags?
It depends on the teabag. Many teabags contain a small amount of polypropylene plastic in the seam and should not be composted. Look for certified compostable bags, or empty loose-leaf tea directly into the compost, and recycle the bag through BRAD.
Can you compost pizza boxes?
Yes — the cardboard itself is compostable. Tear off any heavily greasy sections (these compost slowly) and add the rest as a brown material.