How to make compost in the UK — Here’s something that will change how you see your kitchen bin: the peelings, teabags, cardboard, and grass clippings you throw away every week are worth more to your garden than most things you can buy at a garden centre. Compost — the dark, crumbly, earthy-smelling stuff that makes plants explode with growth — is made entirely from rubbish. And making it yourself is easier than most people think.
In the UK, we collectively throw away around 4.5 million tonnes of food waste a year. A significant portion of that could be turning into free, high-quality compost. This guide will show you exactly how to start, what to put in, what to keep out, and how to avoid the common mistakes that lead to a smelly, slimy mess.
Why Make Your Own Compost?
Commercial compost from garden centres is expensive — a 50-litre bag can cost £8–15 — and for a garden of any size, you’ll go through a lot of it. Home compost is free. It’s also often better quality than what you buy, because you control what goes in. And there’s something deeply satisfying about turning waste into something valuable.
Beyond the garden benefits, composting reduces the amount of waste going to landfill and cuts methane emissions (food waste in landfill produces methane, a potent greenhouse gas). The UK government actually offers subsidised compost bins through many local councils — check your council’s website, as you may be able to buy a bin for as little as £5–10.
📖 Also read: How to Make Free Liquid Fertiliser from Weeds
What You Need to Get Started
You need two things: a container and a mix of materials. That’s it.
- A compost bin — A basic plastic dalek-style bin is perfectly fine for a back garden and is the cheapest option. Wooden slatted bins look better and allow more airflow. If you have space, a two-bay system (one side filling up, one side maturing) is more efficient.
- A mix of ‘browns’ and ‘greens’ — This is the one concept you need to understand, and it’s simpler than it sounds.
The Browns and Greens Rule
Compost needs a balance of carbon-rich ‘brown’ materials and nitrogen-rich ‘green’ materials. Roughly 50/50 by volume is a good starting point.
Browns (carbon-rich, dry materials):
- Cardboard torn up — including cereal boxes, egg boxes, and toilet rolls
- Dead leaves
- Shredded paper and newspaper
- Woody hedge trimmings, chipped or broken small
- Straw
Greens (nitrogen-rich, wet materials):
- Vegetable peelings and fruit scraps
- Tea bags and coffee grounds (check tea bags are plastic-free first — many UK brands now are)
- Grass clippings
- Fresh plant prunings
- Eggshells (these add calcium and are very useful)
💡 UK TIP: After mowing the lawn in spring and summer, you’ll have abundant grass clippings — brilliant greens, but never add them in thick layers or they’ll mat together and go slimy. Mix them immediately with cardboard or dry leaves.
What NOT to Put In
Some things will cause problems — attracting pests, creating bad smells, or not breaking down properly:
- Cooked food, meat, fish, or dairy — these attract rats and foxes. Given how common urban foxes are across UK cities and towns, this is not a risk worth taking.
- Diseased plants — you risk spreading the disease back to your garden.
- Cat or dog waste — contains harmful bacteria.
- Glossy magazine paper — doesn’t break down well.
- Weeds that have gone to seed — the seeds can survive composting and spread everywhere when you use the compost.
How to Build and Manage Your Heap
Start with a layer of scrunched cardboard at the bottom to create airflow. Then alternate layers of greens and browns as they become available — you don’t need to add them in perfect order, just keep adding and mixing.
The two most important things to do regularly:
- Turn it — Every few weeks, use a fork to turn and mix the heap. This introduces oxygen, which speeds up decomposition dramatically. A heap that’s never turned can take 12–18 months. A regularly turned heap can produce compost in 3–4 months.
- Keep it moist — The heap should feel like a wrung-out sponge. In dry summers, add water. In wet British winters, cover the bin with a lid or tarp to stop it becoming waterlogged.
- 📖 Also read: How to Build a Raised Bed Garden from Scratch
How Do You Know When It’s Ready?
Finished compost looks and smells nothing like what you put in. It should be dark brown to black, crumbly, and smell earthy — like a forest floor after rain. You’ll still see occasional bits of eggshell or twig, which is completely normal.
If it still looks like rotting food or smells bad, it needs more time or more turning. If it’s too wet and slimy, add more browns. If it’s too dry and not decomposing, add more greens and water.
When it’s ready, spread it 5–10cm deep over your beds and borders, or mix it into planting holes. Your plants will visibly respond within weeks.
📖 Also read: Stop Throwing Away Seeds — How to Save Them and Grow for Free Next Year
💡 MONEY SAVER: Check gov.uk or your local council’s website for subsidised compost bin schemes. Many UK councils sell bins for £5–15 — a fraction of the retail price of £30–60. Search for “[your council name] compost bin offer”.
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