Why Compost, and What You Actually Need

Every garden and smallholding in Britain produces two things in abundance: waste and a wish for better soil. Composting turns the first into the second, and it costs nothing but a bit of attention. Whether you keep a few hens, run a veg patch behind the shed, or simply want to stop sending peelings to landfill, a decent heap will repay you within a season.

You do not need expensive kit. A bin or a bay made from pallets, a fork, a watering can and somewhere to keep a bag of torn cardboard will do. A lid helps in our wet winters, but a piece of old carpet or a tarpaulin works just as well as anything you can buy.

Find your spot before you start. Heaps do best in a little shade, on bare soil, and within easy reach of the kitchen door. If you have to walk a hundred yards with a bowl of tea leaves, you will have stopped doing it by November.

The Golden Rule: Balance Greens and Browns

Everything else in composting is commentary on this one idea. Greens are wet, soft and rich in nitrogen. Browns are dry, tough and rich in carbon. Get the balance roughly right and the heap will heat, smell sweet and rot down quickly.

• Greens: grass cuttings, vegetable peelings, tea leaves, coffee grounds, nettles, comfrey, spent bedding plants, soft hedge trimmings, hen manure mixed with bedding, fruit scraps.
• Browns: torn-up cardboard with the tape removed, egg boxes, shredded paper, straw, dried leaves, bracken, woodchip, sawdust from untreated timber, loo roll tubes.

Aim for roughly two or three parts brown to one part green by volume. That surprises people, because most of us tip in bucket after bucket of grass and peelings and then wonder why the heap turns to slimy sludge. If in doubt, add more brown. Composting forgives too much carbon far more readily than too much nitrogen.

Keep a bag of torn cardboard beside the bin and throw in a handful every time you empty the kitchen caddy. It takes seconds and it is the difference between compost and a stinking mess.

What to Leave Out

Be generous with most things, but keep these out of the heap:

• Cooked food, meat, fish and dairy, which attract rats and foxes — both already far too interested in your smallholding.
• Perennial weeds in seed or with running roots: couch grass, bindweed, ground elder. They will survive the process and be spread across your beds.
• Diseased material, including blighted tomato foliage and clubroot-infected brassica roots.
• Dog and cat faeces, and used cat litter.
• Glossy magazines, and tea bags with plastic mesh — rip them open or switch to loose leaf.
• Anything treated with weedkiller, and large quantities of evergreen clippings, which are slow and acidic.

Eggshells, citrus peel, onion skins and annual weeds are all perfectly fine.

Turning, Moisture and Temperature

A heap left alone will eventually rot, but it may take a year or more. Turn it and you can cut that to three or four months. Turning lets in air, mixes the wet and dry patches, and shows you what is going on.

For a standard bin, fork everything out onto a sheet and put it back, roughly every three to four weeks through the growing season. If you have two bays, turn from one into the other. It is a job for a dry morning and one of the more satisfying tasks of a smallholding week.

Moisture matters just as much. Aim for the dampness of a wrung-out sponge. In a wet British winter the heap will be too soggy — keep the lid on, add browns, and cover it. In a dry summer it will be too dry, and no amount of turning will help; water it as you turn, a canful at a time.

A well-built heap will reach 50–60°C in the middle within a few days. Push a metal bar into the centre, leave it ten minutes and feel it. Warm is good. Cold usually means too dry or too brown. A sour or ammonia smell means too much green. White mould is normal and completely harmless.

When It Is Ready, and How to Use It

Compost is finished when it looks like dark, crumbly soil, smells earthy rather than sour, and you can no longer recognise what went in. That takes three to six months in a bin, and longer over winter. If eggshells and twiggy bits remain, don't panic — sieve the lot, chuck the lumps into the next heap and use the rest.

Use it as a mulch around fruit bushes and perennials, dig it into the veg beds in autumn, mix it into potting compost for a bit of body, or steep a sackful in a water butt for a fortnight to make a liquid feed. A single bin will give you a barrowload or two a year, and more if you can lay hands on horse muck, spent hen bedding or a neighbour's grass cuttings.

Start with one bin, get your greens and browns roughly right, and turn it when you remember. Everything else is detail, and your soil will thank you for it.