Five ingredients make compost: greens (nitrogen), browns (carbon), water, air and microbes. Remove one and the process stalls.
1. What goes in — and what doesn’t
| Type | Examples |
|---|---|
| Green (wet, nitrogen) | Vegetable and fruit peels, tea leaves, cut grass, spoiled vegetables, manure |
| Brown (dry, carbon) | Dry leaves, straw, paper, cardboard, sawdust, rice husk |
| Avoid | Fish, meat, bones, fat and oil, diseased plants, pet waste |
2. Ratio and moisture
A rough rule: about 2 parts brown to 1 part green by volume. The mix should feel like a wrung-out sponge. If it smells, add browns; if dry, add water and greens.
3. Five methods
| Method | Time | Best for |
|---|---|---|
| Pit compost | 3–4 months | Yards with lots of waste |
| Drum or bin with holes | 2–3 months | Courtyards, balconies |
| Two-bin (turning) | 6–10 weeks | Regular waste, some space |
| Banana circle | Continuous | Yards; humid areas |
| Vermicompost (worms) | 2–3 months | Roofs, kitchen scraps |
4. Troubleshooting
| Problem | Cause | Fix |
|---|---|---|
| Smells | Too wet or too green | Add dry material and turn |
| Dry and not rotting | Too little water | Sprinkle water to moisten |
| Flies or pests | Food left exposed | Bury waste in soil or dry leaves; cover |
| Not heating up | Pile too small or too little green | Build it bigger (≥1 m), add greens and water |
5. Is it ready?
Dark, crumbly, earthy-smelling, with original materials no longer recognisable. Spread a 3–5 cm layer on beds, or mix in at 30–40% of pot soil.
Don’t put raw or half-rotted compost directly at seedling roots; it can burn them.