Harriet Cooper
Why Compost Deserves a Corner of Your Plot
There is something quietly satisfying about tipping a bowl of potato peelings onto a heap in February and, by late summer, digging out handfuls of dark, crumbly compost that smells of a woodland floor. Composting is the closest thing to alchemy a smallholder gets, and it costs almost nothing. It keeps kitchen and garden waste out of the bin lorry, feeds your soil, and saves you buying bagged compost by the trailer-load.
It is also less fussy than many people imagine. You do not need an expensive bin, a thermometer or a degree in soil science. You need roughly the right mix, a little air, and enough patience to let the microbes get on with it.
Greens and Browns: The Balance That Matters
Everything you compost is either a green or a brown, and the whole craft boils down to keeping them in proportion. Greens are wet and nitrogen-rich; browns are dry and carbon-rich. Microbes need both, and they need far more carbon than nitrogen. Aim for roughly two to four parts browns to one part greens by volume.
- Greens: vegetable peelings, tea leaves, coffee grounds, grass clippings, fresh annual weeds before they seed, comfrey leaves, spent bedding plants, herbivore manure.
- Browns: torn cardboard, newspaper, egg boxes, loo roll tubes, straw, woodchip, autumn leaves, shredded paper, untreated sawdust.
Get it wrong in the green direction and you will know about it: a slimy, sour-smelling heap that attracts flies. Get it too brown and dry and nothing much happens for months. Keep a bag of shredded cardboard beside the bin and you can correct a soggy heap in seconds.
Choosing a Bin and Siting It Well
A heap on bare soil is the gold standard — worms and beneficial fungi move in freely from below. If you want something tidier, a wooden pallet bay or a lidded plastic bin both work beautifully. Whichever you choose, follow a few rules.
- Stand it directly on soil or grass, not on concrete or paving.
- Choose a level, well-drained spot in light shade; full sun dries a heap out quickly.
- Keep it within easy reach of the kitchen door and the veg patch, or you will stop using it.
- Make it big enough to hold heat: at least a cubic metre of material once full.
If rats are a worry, a lidded bin with a base plate is a sensible choice, and you can still keep a second, open heap for garden waste only.
Air and Moisture: Where Most Heaps Go Wrong
The composting organisms that do the fast work need oxygen. An airless heap turns anaerobic, which is what produces that sharp, vinegary stink. Turn your compost every two to four weeks with a fork, bringing the outside to the middle and the middle to the outside. That single job speeds everything up more than anything else you can do.
Moisture matters just as much. The heap should feel like a wrung-out sponge — damp, never dripping. Do the squeeze test: grab a handful from the middle and squeeze. If water runs out, it is too wet; fork in cardboard or straw and turn it. If it crumbles and feels dusty, water it as you turn, or add grass clippings and kitchen scraps.
In a cold snap, do not panic if the heap goes quiet. It will start up again in spring. A covering of old carpet or a tarpaulin keeps the worst of the rain off through winter while still letting air in at the sides.
What to Add — and What to Leave Out
Your heap is a living system, so feed it thoughtfully. The following are best kept away from an open compost heap.
- Cooked food, meat, fish and dairy, which attract rats and foxes.
- Dog and cat faeces, and used cat litter.
- Perennial weeds such as bindweed, couch grass and ground elder, plus any weed that has set seed.
- Diseased plant material, especially potato and tomato foliage with blight.
- Glossy magazines, coal ash and treated or painted timber.
Grass clippings are fine in thin layers mixed with browns, but never tip on a thick, solid mat — that is a recipe for a slimy, smelly heap. If you have a glut after mowing, spread some as a mulch instead.
When It Is Ready, and How to Use It
A well-managed heap gives you compost in three to four months over summer. A slow, unturned one may take nine to twelve. You will know it is done when it is dark, crumbly, cool, and smells sweet and earthy, with few recognisable bits left. If you can still spot eggshell and twigs, sieve it and return the lumps to the next heap.
Use it as a mulch around fruit bushes and perennials, fork it into the top few inches of veg beds in autumn, or mix it with loam and leafmould for a fine homemade potting blend. A heap that is working properly will also give you a bonus: the liquid that drains from it, diluted ten to one in a watering can, makes a gentle feed for hungry courgettes and tomatoes.
Start with one bin, keep a stash of torn cardboard nearby, and turn it when you think of it. That is genuinely all there is to it.
