How to make a compost heap

Inspired by a helpful YouTube guide. This walk-through draws on the "Introduction to composting" video from the RHS — the Royal Horticultural Society — which covers the basics clearly and without any fuss. Worth watching before you start: it explains the green and brown balance in a way that actually sticks.

1. Choose a good spot and decide on your setup

A compost heap needs some warmth and moisture to work properly, so a partially shaded spot is ideal — full scorching sun dries it out, deep shade slows things right down.

You can compost directly on the ground (just mark out a square with timber boards or bricks) or use a purpose-built bin. Plastic dalek bins are cheap and retain heat well. Open timber bays are better for larger volumes and easier to turn. Either works.

Put it somewhere with reasonable access. You will be adding to it regularly, and eventually you need to get a wheelbarrow in to take the finished compost out.

2. Understand the green and brown balance

Composting is essentially controlled decomposition, and two types of material drive it. Greens are nitrogen-rich: fresh grass clippings, vegetable peelings, tea bags, coffee grounds, young weeds. Browns are carbon-rich: cardboard, dry leaves, straw, shredded paper, wood chippings.

Aim for roughly equal volumes of each by weight. Too many greens and the heap turns slimy and smells. Too many browns and it just sits there doing very little. Both problems are easy to fix once you know what to look for.

3. Build the heap in layers

Start with a layer of coarse material — twiggy prunings or scrunched cardboard — to let air circulate at the base. Then alternate green and brown layers as you add material.

You don't need to be too precise about it. Chuck in a few kitchen scraps, cover with torn-up cardboard or a handful of dry leaves, repeat. Over time the layers blend together and the whole thing heats up.

4. Keep it moist but not waterlogged

Microorganisms need moisture to break down organic matter, so a dry heap barely composts at all. Squeeze a handful — it should feel like a wrung-out sponge. Damp throughout, but not dripping.

If it dries out in summer, water it gently and turn the material. If it gets waterlogged after heavy rain, add more browns and turn. A loose cover — an old piece of carpet or a lid — helps keep the moisture level stable without cutting off air.

5. Know what to leave out

Most plant-based kitchen and garden waste is fine. That said, certain things will cause problems. Cooked food, meat, fish, and dairy attract rats — leave them out entirely. Dog or cat waste carries pathogens and shouldn't go in a home heap.

Perennial weeds like bindweed, couch grass, and ground elder can survive the composting process and spread when you use the finished material. Either bin them separately, drown them in a bucket of water for a few weeks first, or get them in a council collection bag. Diseased plant material is also best kept out.

6. Turn the heap to speed things up

Turning introduces oxygen, which activates decomposition and stops the heap going anaerobic and smelly. A turned heap composts in roughly three to six months. An unturned one takes nearer a year.

You don't have to turn at all if you'd rather leave it — it will still work, just more slowly. If you do turn, do it once every few weeks in the warmer months, using a fork to mix the outer material into the centre where most of the heat builds up.

7. Recognise when the compost is ready

Finished compost is dark brown, crumbly, and smells earthy — similar to woodland soil. You shouldn't be able to make out the original materials any more. If you can still see grass clippings or peel, it needs longer.

Mind you, the compost at the bottom of the heap is usually ready well before the top layers. Most people dig from the bottom or side, take what's ready, and leave the rest to carry on.

When to call a handyman

Richard doesn't do composting, but he can build a solid timber compost bay, put up a garden shed, lay a path through the vegetable plot, or tackle any outdoor structure job around your garden. Just get in touch.