What Is Composting and Why Does It Matter?
Composting is the natural process of recycling organic matter — food scraps, garden clippings, paper — into a nutrient-rich soil amendment called compost. When organic waste ends up in landfill, it decomposes without oxygen and produces methane, a potent greenhouse gas. Composting at home diverts that waste, reduces landfill pressure, and gives you a free, powerful fertiliser for your garden or houseplants.
Choosing the Right Composting Method
Your space and lifestyle will determine which method suits you best:
- Outdoor compost bin or heap: Best for gardens with outdoor space. Handles large volumes and a wide range of materials.
- Worm farm (vermicomposting): Compact, odourless, and great for small spaces or flats. Worms break down food scraps quickly into rich "worm castings."
- Bokashi system: An indoor fermentation method that processes all food waste including meat and dairy. Requires a special bran inoculant.
- Tumbler composter: A sealed, rotating drum that speeds up decomposition and keeps out pests. Great for suburban gardens.
What You Can (and Can't) Compost
✅ Yes — Add These
- Fruit and vegetable scraps
- Coffee grounds and paper filters
- Tea leaves and bags (paper-based only)
- Eggshells
- Grass clippings, leaves, and plant trimmings
- Cardboard and newspaper (torn into pieces)
- Hair and nail clippings
❌ No — Avoid These (Standard Compost)
- Meat, fish, and bones
- Dairy products
- Oily or greasy foods
- Diseased plants
- Pet waste
- Glossy paper or magazines
The Green-to-Brown Ratio
Healthy compost needs a balance of:
- Greens (nitrogen-rich): Fruit scraps, vegetable peelings, fresh grass clippings, coffee grounds.
- Browns (carbon-rich): Dry leaves, cardboard, straw, paper, wood chips.
Aim for roughly 2–3 parts brown to 1 part green by volume. Too many greens and the pile becomes slimy and smelly. Too many browns and decomposition slows down significantly.
Step-by-Step: Setting Up Your First Bin
- Choose your location: A shaded, level spot with good drainage. Avoid direct sun which dries it out too fast.
- Start with a base layer: Add a 10–15cm layer of coarse browns (twigs, straw) to aid drainage and airflow.
- Add your first materials: Layer greens and browns, keeping the moisture level similar to a wrung-out sponge.
- Turn it regularly: Every 1–2 weeks, turn the pile with a fork to introduce oxygen. This speeds decomposition and prevents odours.
- Monitor moisture: If it's too dry, add water or more greens. If it's soggy or smelly, add more browns and turn it.
- Wait and harvest: Depending on conditions, compost is ready in 2–6 months. It should look dark, crumbly, and smell earthy.
Troubleshooting Common Problems
| Problem | Likely Cause | Fix |
|---|---|---|
| Smells bad | Too many greens, too wet | Add browns, turn pile |
| Not breaking down | Too dry or too many browns | Add water, add greens |
| Pests attracted | Food scraps exposed | Bury scraps in centre, use a lidded bin |
Composting is one of the most rewarding sustainable habits you can build. Once it becomes routine, you'll wonder how you ever threw food scraps in the bin.