Make compost

Pile green stuff, brown stuff, and dung, keep it damp, and let it rot into rich dark food for the soil.

easy⏳ a season, mostly waitingtradition — not yet hand-tested

Soil gets tired. Every harvest carries food out of the ground, and if nothing goes back in, each year's crop is smaller than the last. Compost is how you put it back: a pile of dead plants and dung that rots down into dark, crumbly, sweet-smelling soil-food. It turns even poor sand or sticky clay into ground worth planting.

Rot is done by living things — countless tiny creatures too small to see — and they need food, water, and air. Give them all three and a pile becomes compost in a season; starve them of one and it sits there, or turns to stinking sludge.

You need

• Green stuff — fresh, moist, recently alive: grass, fresh weeds (before they seed), vegetable scraps, kitchen peelings. This is the rich food that makes the pile heat up.
• Brown stuff — dry and dead: fallen leaves, straw, dry grass, chopped twigs, dead plant stalks. This is the slow fuel; it keeps air in the pile.
• Dung, if you can get it — from grass-eaters (cow, horse, sheep, goat, rabbit) or chickens. It kicks the rot into high gear. Never dog, cat, pig, or human dung — those carry diseases that can pass to people through food crops.
• Water — the pile must stay damp all the way through.
• A shady, bare-earth spot — shade so it doesn't dry out; bare earth so worms and soil creatures can climb in from below.
• A stick or wooden fork — for turning the pile.

Steps

1. Pick the spot. Bare ground, some shade, close to the garden — and downwind of where you sleep.
2. Gather browns and greens in two separate heaps so you can control the mix. Chop or break everything to hand-size or smaller — small pieces rot far faster.
3. Build in layers, like a lasagne. A layer of browns about 10 cm thick, then a layer of greens about 5 cm, a scatter of dung or a shovel of plain soil, a splash of water. Repeat. Aim for roughly 2 to 3 parts brown to 1 part green by volume.
4. Make it big enough to work. A pile smaller than about 1 metre wide, deep, and tall cannot hold its heat. Build to that size, even if it takes weeks. Bigger than 1.5 metres and the middle can't breathe.
5. Keep it damp like a wrung-out sponge. Squeeze a handful from inside: a drop or two should appear, no more. Too dry — water it. Sodden — fork in dry browns. Cover the top with straw, leaves, or bark slabs so rain can't drown it and sun can't bake it.
6. Feel it heat, then turn it. Within a week a good pile gets noticeably warm inside — even steaming on cold mornings. That heat is the rot working; it also kills weed seeds and disease. When the warmth fades (every 2–3 weeks), turn the pile: fork it over so the outside ends up in the middle and the heat restarts. Three or four turns over a season is plenty.
7. Know when it's done. Finished compost is dark brown to black, crumbly, and smells like forest floor after rain. You should not recognise what went in, except a few twigs. This takes 2–4 months with turning, up to a year if you just leave it.
8. Use it. Spread 2–5 cm on beds before planting and scratch it into the top of the soil, or throw a handful in each planting hole.

Watch out

• A stinking, slimy pile means too wet and too green — it has gone airless. Fork it apart, mix in lots of dry browns, rebuild.
• A pile that does nothing is too dry, too brown, or too small. Water it, add greens or dung, and build it up to the metre mark.
• Meat, fat, bones, and cooked food draw rats, flies, and scavengers. Leave them out.
• Raw dung straight onto food crops can make you badly ill. Dung goes into the pile and comes out only as finished compost — and let compost with dung in it fully finish, months not weeks, before it touches anything you'll eat raw.
• Weeds carrying seeds, and diseased plants survive a cool pile and come back to haunt your beds. Only a hot, turned pile kills them; if your pile runs cool, burn or dump those instead.
• Poisonous or waxy leaves (like walnut leaves, or thick evergreen needles) rot slowly and some hold back plant growth. Keep them to a small share or leave them out.

How it works

The heat is billions of tiny living things eating the pile and giving off warmth, the way a crowd warms a room. Greens and dung are their rich food; browns are their slow food and their air supply; water lets them move and eat. When the food runs low the pile cools, and worms move in to finish the job.