Composting Kitchen Scraps at Home: Bins, Worms and What Goes In

Composting is nature's recycling. Microbes, fungi and small creatures break down plant scraps into a rich, earthy material that improves garden soil. It also keeps food scraps out of the rubbish, where they would otherwise be buried and break down without much oxygen.

The basic recipe: greens and browns

Compost likes a balance of nitrogen-rich materials, often called greens, and carbon-rich materials, called browns. Greens include fruit and vegetable scraps, coffee grounds, tea leaves and fresh grass clippings. Browns include dry leaves, shredded paper, cardboard and straw. A rough rule of thumb is about two or three parts brown to one part green by volume. If the pile smells sour or looks slimy, add more browns. If it is dry and not breaking down, add greens and a splash of water.

Choosing a method

A backyard bin or tumbler works well if you have outdoor space and produce garden waste. A pile needs air, moisture like a wrung-out sponge, and time, usually a few months to a year. For apartments, a worm bin, or vermicomposting, uses red wigglers to eat scraps in a small container and produces rich castings. Some people use sealed bokashi buckets, which ferment scraps first and then need to be buried or added to another compost system. Many cities also offer curbside food scrap collection.

A hot pile, which has plenty of green material, good moisture and regular turning, can reach temperatures that speed decomposition and help break down some weed seeds, but most home piles run cooler and simply take longer. Either way is fine. If you cannot be bothered to turn the pile, poke a few holes in it with a garden fork or stick every now and then to let in air, and chop larger scraps into smaller pieces so they break down faster.

What to leave out

Avoid meat, fish, dairy, oils and cooked greasy food in a home pile, which can attract pests and smell bad. Do not add pet waste or diseased plants. Seeds from weeds can survive a cool pile, so keep them out unless your compost gets hot. Seed shells, nut shells and fruit pits break down slowly and are better chopped or left out.

Troubleshooting

Fruit flies are common and can be reduced by burying fresh scraps under a layer of browns. A pile that is cold and not decomposing often needs more nitrogen, moisture or turning. Turning every couple of weeks adds air and speeds the process. If animals visit, use a closed bin or a mesh lid.

Using finished compost

Finished compost is dark, crumbly and smells like forest soil. Mix it into garden beds, sprinkle it around plants as a top dressing, or blend a portion into potting mix. Do not use it as the only growing medium for seedlings, since it can be too rich.

Even a small scrap bucket and a drop-off programme are worthwhile. Composting teaches you how much of your food waste is actually usable material.

This article is general information, not medical advice.