Why a compost bin earns its keep in a small backyard

Even the smallest UK backyard can produce a steady supply of homemade compost. A bin turns kitchen scraps, grass clippings and prunings into dark, crumbly organic matter that improves soil structure, feeds plants and saves you a trip to the garden centre. It also cuts down on waste sent to landfill, where it would release methane. For allotment holders and backyard growers alike, compost is the closest thing to free gold. You do not need a huge plot or expensive kit. A modest 200-litre bin tucked beside a shed or fence will do the job, provided you get the basics right.

Choose a bin that suits your space

Plastic dalek bins are cheap, widely available and fit neatly into corners. They hold around 220 to 330 litres, which is plenty for a small household. Tumblers are another option: they make turning easy but dry out faster and hold less. Wooden slatted bins look handsome and breathe well, though they can be pricey. If you mainly compost kitchen scraps, a wormery is brilliant, but it cannot cope with large amounts of garden waste.

Site your bin on bare soil if possible. Worms and microbes can then move in from below, and excess moisture drains away. If you must stand it on paving, put a layer of twigs or scrunched cardboard at the base. A spot in partial shade is ideal, as full sun can dry the contents too quickly. In a tiny yard, consider two bins side by side: fill one while the other matures.

The golden rule: balance greens and browns

Composting is simple biology. Greens are nitrogen-rich and wet: grass clippings, vegetable peelings, tea bags, coffee grounds, annual weeds and soft plant trimmings. Browns are carbon-rich and dry: cardboard, paper, straw, autumn leaves, woodchip, sawdust, egg boxes and toilet roll tubes. Aim for roughly two parts browns to one part greens by volume. If your bin smells sour or slimy, you have too many greens. Add a handful of torn cardboard, stir it in, and the problem usually disappears.

• Greens: fruit and veg scraps, grass, fresh leaves, tea, coffee, young weeds.
• Browns: cardboard, newspaper, straw, dry leaves, wood shavings, paper bags.
• Chop: larger items into smaller pieces to speed up decomposition.
• Layer: alternate handfuls of greens and browns as you add them.

Keep it moist and turn it now and then

Your compost should feel like a wrung-out sponge: damp but not dripping. Squeeze a handful. If water runs out, it is too wet. If it feels dusty, it is too dry. To fix a dry bin, add fresh greens or a little water from a watering can. To fix a soggy bin, fork in plenty of browns and turn the contents.

Turning introduces oxygen, which keeps the aerobic microbes working. In warm weather, turn every two to four weeks with a garden fork or compost aerator. In winter, you can leave it alone. Tumblers need a spin every few days, but do not overdo it or the contents will stay cold. A well-turned bin can heat up to 60°C, speeding up the process and killing some weed seeds. Even without turning, a cool bin will eventually rot down; it just takes longer.

What to leave out

Not everything belongs in a small backyard bin. Cooked food, meat, fish and dairy attract rats and foxes. Perennial weeds such as bindweed, dock and dandelion roots can survive unless your bin gets really hot. Diseased plants, including blight-infected tomatoes and clubroot-affected brassicas, should be binned or burned. Also avoid pet waste, nappies, glossy magazines, treated wood and anything plastic. When in doubt, leave it out. A simple, clean bin is a happy bin.

Troubleshooting and using your compost

Most problems have a straightforward fix. Smells like rotten eggs? Too wet and airless: add browns and turn. Nothing happening? Too dry or lacking greens: water and add grass clippings. Fruit flies? Bury kitchen scraps in the middle of the bin. Cold weather slows everything down, so do not panic if your bin sits idle from November to February.

When the compost is dark, crumbly and smells earthy, it is ready. This can take six to twelve months in a cool bin, or as little as three months if you turn regularly. Sieve out any lumps and return them to the next batch. Use your compost as a mulch around shrubs and perennials, dig it into vegetable beds, or mix it with grit and loam for potting. However small your backyard, that rich, homemade organic matter is a quiet triumph.