Composting turns everyday kitchen scraps and garden waste into a dark, crumbly material that improves almost any soil. It cuts household waste, saves money on soil improvers and is easier than it looks. You do not need a big garden: a compost bin fits in a small yard, and there are options for balconies too.
How composting works
Bacteria, fungi, worms and insects break down organic material. They need four things: carbon, nitrogen, moisture and air. Get the balance roughly right and the process takes care of itself.
Greens and browns
Compost ingredients fall into two groups.
Greens are rich in nitrogen, usually moist and fresh:
- Fruit and vegetable peelings
- Coffee grounds and tea leaves
- Grass clippings
- Fresh plant trimmings
Browns are rich in carbon, usually dry:
- Dry leaves
- Shredded cardboard and plain paper
- Straw and wood chips
- Egg boxes and paper towel rolls
A simple rule of thumb is to add roughly equal volumes of greens and browns, or slightly more browns. Too many greens makes the heap wet and smelly. Too many browns slows everything down.
What not to compost
- Meat, fish and bones, which attract pests
- Dairy products and oily foods
- Pet waste from cats and dogs
- Diseased plants and perennial weeds with roots or seeds
- Glossy or coated paper
- Ash from coal or treated wood
Setting up your bin
Place the bin on bare soil if possible, so worms and microorganisms can move in, in a spot with some shade. Start with a layer of twigs or coarse material at the bottom for airflow, then add greens and browns in layers as you collect them.
Keeping it healthy
- Moisture: the heap should feel like a wrung-out sponge. Add water if dry, add browns if soggy.
- Air: turn the heap with a garden fork every few weeks. This speeds up decomposition and prevents bad smells.
- Size: chop larger material into smaller pieces so it breaks down faster.
Troubleshooting
| Problem | Likely cause | Fix |
|---|---|---|
| Rotten smell | Too wet, too many greens | Add browns and turn |
| Nothing happening | Too dry or too many browns | Add greens and water |
| Flies | Exposed food scraps | Bury scraps under browns |
| Rodents | Meat or cooked food | Remove, use a closed bin |
When is it ready?
Finished compost is dark brown, crumbly and smells earthy, and you can no longer recognise the original ingredients. In a well-managed bin this takes about three to six months. In a heap that is left alone, it can take a year or more.
Using your compost
- Spread a few centimetres over garden beds as mulch
- Mix into planting holes for new plants
- Blend with potting mix for containers, about one part compost to three parts mix
- Top-dress lawns lightly in spring
Composting without a garden
If you only have a balcony, a worm bin or a sealed bokashi bucket can process kitchen scraps indoors or outdoors with very little smell. Both produce material you can add to pots and planters.
Quick answers
Does compost smell? A healthy compost heap smells earthy. A bad smell usually means too many wet “greens” or not enough air. Add dry “browns” such as cardboard or leaves and turn the pile.
How long does compost take? A well-managed, regularly turned heap can be ready in a few months. A pile left alone may take a year or more, but it still breaks down eventually.
Can I compost in a flat? Yes. Small indoor or balcony systems such as worm bins (vermicomposting) or sealed bokashi buckets work well in limited space.
What should never go in compost? Avoid meat, fish, dairy, cooked oily food, pet waste from cats and dogs, diseased plants and weeds that have set seed. These can attract pests, spread disease or survive the process.
How do I know when it is ready? Finished compost is dark, crumbly and smells like soil, and you should not be able to recognise the original materials.
