There’s something quietly pleasing about transforming yesterday’s vegetable peelings into dark crumbly soil that makes other things grow. I started composting thirty years ago, before it got trendy and everyone began shouting about how virtuous it was. Back then nobody cared if you composted, you just did it if you had a sensible approach to garden waste. Looking at all the advice on composting nowadays what amazes me is how complicated people make it. There are endless ratios and bin designs that make something so simple seem overwhelmingly technical.
The fact is that the average UK household throws away 6.4 million tonnes of household food and drink waste each year (source) and most of that could go on your compost heap rather than into landfill where it will produce methane as it rots. Methane in landfill is made up of roughly equal parts methane and carbon dioxide (source), in your compost heap the gases escape into the air instead.
The thing about composting is that it doesn’t matter if you understand any of those scientific details, whether you have a big garden or a tiny balcony, whether you follow all my advice or just wing it. I made my first compost heap thirty years ago after reading none of this, just shoving autumn leaves and grass cuttings into a heap in the corner of my garden. It worked okay. Not perfectly, not quickly, but it worked. In the intervening years I’ve learned how to do it better, faster, and in much smaller spaces than that bounteous garden corner allowed.
## Understanding What Works
Composting is not magic, or even chemistry. It’s biology; a bunch of micro-organisms doing a job if you supply them with the conditions they need. To keep things simple there are four factors they require: Carbon, Nitrogen, Oxygen, and H2O.
Carbon to Nitrogen Ratio
Carbon and Nitrogen are elements found in organic matter. Organic matter with a higher carbon content is ‘brown’ – think dead leaves, straw, or paper. Nitrogen rich material is ‘green’ – grass clippings, vegetable waste, or cereal stalks. Your compost should have roughly three parts brown material to one part green. The ideal carbon to nitrogen ration for hot composting is between 25:1 and 30:1 (source). As it composts and matures that ratio reduces to between 10: 1 and 15:1 in finished compost (source).
Don’t worry about being too precise with your ratios. I’ve never measured mine; I just try and remember to add roughly three buckets of brown stuff to every bucket of kitchen scraps. If your heap starts to smell like ammoniac gas add more browns. If it doesn’t seem to be composting quickly enough, add more greens.
Maintaining Moisture Levels
Your heap needs to be moist for the microorganisms to do their work. How moist? About 40-60% moisture content (source). Grab your compost and squeeze. It should feel like a wrung-out sponge. Too dry and decomposition slows, too wet and your pile becomes anaerobic and smelly.
Oxygen and Pathogens
Hopefully you’re turning your pile regularly to let air in. As long as it’s aerated enough your compost will reach temperatures of at least 131°F (55°C) for three days during the decomposition process (source). Pathogens are killed by heat, so you don’t need to do anything extra to create pathogen-free compost beyond building and maintaining a heap of sufficient size.
## Equipment for Every Lifestyle
Larger Gardens
If you’re lucky enough to have space then stick with good old fashioned compost heaps. They are efficient, take large volumes of material, and won’t set you back very much money. To qualify as a heap it should be at least 1m x 1m in area (source). Smaller than this and it’s difficult to get enough mass to generate and hold the heat needed to decompose efficiently. Bins that are smaller than 1 cubic metre volume are also considerably less efficient at breaking down material (source).
Our system is made up of three ‘bays’ built from reclaimed pallets held together with chicken wire. The idea is that one bay is where you add new material, one is ‘hotting up’ and one is ready to harvest. Each bay is roughly 1.2m square which gives enough volume for effective hot composting and is still a comfortable size to turn by hand. I paid about £15 for chicken wire and fixings for each bay when I built them, plus the cost of pallets which was minimal since the farmers were only too happy to get rid of them.
Smaller Gardens
So far as compost bins go, if you have the space to keep one in your garden, go large. Plastic ‘dalek’ style bins are perfectly functional but their size is really the limiting factor. They are often too small to heat up properly which means that decomposition is much slower. They are better suited to continuous composting where you add material regularly and then harvest compost from the bottom of the bin every few months.
Don’t bother with tumbler composters. The principle is sound; you get faster results because it’s easier to turn them, but they’re too small to hold enough material. They dry out easily and thus don’t heat up properly either. They will work and are great for people that want something neat and tidy but be prepared for it to take six to twelve months to get finished compost. With a larger hot heap you should be getting there in three to six months.
Flatdwellers
Your best bet for getting the most out of your kitchen waste are worms. Worm composting, or vermiculture, is actually effective. A well maintained worm bin will produce usable compost in three to six months and can handle more kitchen waste than you might think. You can get specially made worm composting bins for between £40-80 or you can grab a plastic storage box with holes drilled in the bottom and sides.
Fermenting your kitchen waste using bokashi is another viable option for indoors. It’s not composting strictly speaking but it achieves many of the same results. Bokashi is a Japanese method of fermenting organic waste that allows you to dispose of any food scraps including meat and fish. Bury the fermented material in soil or dig it all out and add it to your outdoor compost heap once it’s done. Don’t let the method put you off; it works.
Balconies
Outdoor composting on a balcony is going to be limited by space. With a sensible setup you can compost small amounts of waste. Use a stack of storage boxes with holes in the bottom of the top box and holes in the sides of all of them. Drill the holes in the bottom box so they line up with the box underneath – this creates drainage. Fill the bottom box with coarse material to aid drainage, add kitchen waste and garden waste in layers, turning once a week with a hand fork.
You will be limited by volume here. Enough to deal with peelings from one or two people in a flat but not masses of food waste. You’ll also need to pay more attention to it than a garden compost heap. A wet winter will kill it if you don’t keep adding brown material. In summer it will dry out unless you’re religious about watering it.
## Mistakes to Avoid
Mistake #1 – Starting too small. This is probably the most common mistake that I see from people new to composting. Trying to compost in containers that are too small just makes life harder for you and the compost organisms. A small container will eventually produce compost but it’ll take twice as long and you’ll need to constantly monitor moisture levels and try to get the carbon:nitrogen ratio ‘just right’. If your space won’t allow a decent sized heap then accept that your system will work differently and learn its limitations.
Mistake #2 – Adding rubbish. Meat, fish, cooked food and dairy products don’t belong on your compost heap. They’ll attract rats and create pockets of anaerobic decomposition that smell horrible. If you’re hot composting and have enough volume to get and maintain high temperatures, you could include these materials but it’s more trouble than it’s worth. Think veg peelings, coffee grounds, eggshells, fruit waste, and leaves/garden waste when adding to your compost.
Mistake #3 – Expectations of quick results. Composting doesn’t happen overnight, even in ideal conditions. If you’re hot composting and everything goes perfectly you might be looking at three months to get useable compost. More likely is that you’ll get it in six months. If you’re cold composting (which you are if you don’t turn your heap regularly) it could take a year or more. Be prepared to wait.
Mistake #4 – Being Too Precise. In the quest for perfect compost some people try and weigh everything they put onto their heap. Yes, carbon:nitrogen ratios matter but so does consistency. If you find yourself constantly weighing kitchen scraps against brown materials, stop. If you’re adding kitchen scraps daily you should be adding roughly three times as much brown material. Smells bad? Add browns. Doesn’t seem to be composting? Add greens.
## Final Thoughts on Home Composting
All of the research I could find supports home composting. Studies show that compost systems can handle the vast majority of household organic waste while creating a product that performs just as well as commercially produced compost. Research looking at pathogen kill rates shows hot composting, when done correctly, more than does the job.
Producing your own compost at home also has environmental benefits. Putting your organic waste onto a compost heap instead of landfill prevents methane being created during decomposition and saves on collection vehicles having to transport it to a facility. Using that compost in your garden can improve soil quality in ways that chemical fertilizers cannot.
I especially like that research backs up my own experience that there are multiple ways to successfully compost at home. Large hot heaps are great but even small ‘cold’ heaps produce excellent results if you’re patient. Worm composting works and is good at fitting into smaller spaces. Simply burying food waste and letting it rot over 18-24 months is also effective.
The important thing is you keep things compostable. Meat and cooked food might be tougher to deal with but if you’re happy putting that stuff onto your heap then great. Ferment it first with bokashi if you’re worried about smells. The world is your composting oyster.
As with everything on this website I’ll finish with some ideas for how to tailor composting to your lifestyle.
Renting with a small outdoor space
Most composting systems can be placed on council property. Check your tenancy agreement but I’ve never known a landlord to object to a compost bin. If you’re limited on outdoor space then container composting is your best bet. A wormery would also work but needs some outdoor space to get rid of the ‘tea’ that you’ll need to harvest every few months.
Lots of garden
If you have the space, experiment. Keep a hot heap going for your garden waste, add a small bin for daily kitchen waste, and start a leaf pile that will take two years to decompose. You can compost things you wouldn’t have space for in small heaps, prunings, more grass clippings. Compost EVERYTHING YOU CAN.
I want to compost but I don’t have time for faff
Cold composting isn’t much hassle. Get an enclosed bin (optional) and start stacking. Check moisture levels once a month and turn every few months if you can be bothered. Add layer upon layer and wait. It’ll decompose.
How Much Will This Cost Me?
Setting up for composting depends on the route you choose to go. Basic heap? Pallets + wire = £15-£25. Plastic bin? £25-£50. Tumbling composter? £80-£150. Worm composting? £40-£80.
You’ll need a garden fork to turn heaps and bins. A compost thermometer doesn’t cost much but can be handy. Add another £20-£30 there.
| Approach | Minimum Spend | Maximum Spend |
|---|---|---|
| Basic heap | £15 | £25 |
| Plastic compost bin | £25 | £50 |
| Tumbler style composter | £80 | £150 |
| Worm composting system | £40 | £80 |
| Tools | £20 | £30 |
| Total | £80 | £275 |
## Let’s Compost!
Depending on how much time you spend reading this you could be composting within a week. Here’s my suggested steps to get you started:
Step 1 – Choose Your Composting System (1 week)
Do you have space for a heap? Balcony only? Indoor? Take stock of where you live, how much waste you want to compost, and how much time you’re willing to spend. Garden bigger than 5mx5m? Get a proper heap or three bay system. Small to medium space? Choose between bins, tumblers, or worm composting. Allow £20-£40 for the basic setup but £80-£150 for something with bells and whistles.
Step 2 – Get It Ready To Go (1 week)
Once you’ve bought/constructed your system it’s time to put it somewhere sensible. That’s usually a partial shady position with good drainage and close to where you’ll be adding waste. Heap composting? Dig a hole and lay some coarse material (prunings, straw) at the bottom. Add your first kitchen scraps and garden waste. Water if it’s looking dry.
Step 3 – Build Your Routine (3-6 weeks)
Get into a rhythm of adding stuff and occasionally checking moisture levels. Kitchen waste will likely be added daily; heap additions 2-3 times per week with sufficient brown material. You can turn your pile once every couple of months if you want to speed things up. If you’ve gone for worm composting then add your first scraps now.
Step 4 – Monitor and Adapt (2-4 months)
Look for signs of decomposition. With heaps you should see volume reduce, temperatures rise (hot heaps), and it should smell like earth. If it smells awful or is attracting flies adjust your moisture levels and brown:green balance. Worm composting systems need food and moisture too. Harvest your first compost after three to four months.
Step 5 – Harvest and Use (6 months+)
Depending on the route you’ve chosen and the conditions you’ve created it could take three months to get finished compost. If you’re happy cold composting with little effort then allow 6-18 months. Use your compost as mulch, soil amendment or in a homemade potting mix.
If you’re just starting out try not to worry too much. You can always adjust your setup as you learn what works and doesn’t work in your garden.
