Composting at home is such a great way to help the environment, and it’s one of the best tricks for helping your garden flourish. Not only will it help you deal with kitchen and garden waste, the nutrients that you’d normally throw away are perfect for restoring depleted soil and giving your plants everything they need to thrive.
If you’ve never tried composting before, it can be tricky to know where to start. What type of bin do you choose, and what can go in it? How do you know when compost is done, and do you always have to “turn” your compost?
We’ve put together a complete beginners guide, with composting tips – and garden compost bin ideas – to help you find the answers to all of these questions and more.
6 Reasons to Start Composting
So, what is composting all about? Composting is a way to use up lots of your kitchen scraps, garden waste and even occasionally some household rubbish, by helping it to quickly decompose into an organic soil to feed your plants. Here are some of the best reasons to start composting:
- You get a free, high-quality soil conditioner. A layer of compose tops up the nutrients in your garden soil, and helps the soil retain moisture.
- Recycle more waste… Savvy households can turn as much as 30% of their rubbish into composting.
- …So less goes to landfill. Given that organic matter (like food scraps) can’t decompose safely in landfill – instead producing methane gas – this is hugely important for the environment.
- Better than chemicals. Composting acts as a natural alternative to chemical fertilisers, so it’s less harmful to the earth and safer for pets and children.
- Adds healthy organisms into the soil. Your compost will become a home to micro-organisms dedicated to aerating your soil, breaking down organic materials for plants to absorb and fending off types of plant disease.
- It’s cost-effective. Did we mention, it’s totally free?
What are the different kinds of compost bins?
Once you start looking into composting in your own garden, you’ll realise there are lots of different types of bin. It’s easy to get a bit overwhelmed! To save you the confusion, here’s a quick explanation of the most common types of compost bin and how they work.
Worm bins. Also called “wormeries” – and the clue to how they work is in the name. Worm bins rely on a little colony of wriggly worm friends to turn kitchen and garden waste into compost and concentrated liquid fertiliser (sometimes called “worm soup” or “worm tea”). Worm bins are only good for low volumes of waste, but are ideal for composting in smaller homes and flats.
Closed compost bins. Closed compost bins are usually made from wood or plastic, and feature a heavy lid that keeps the compost sealed from the elements (although there should be drainage holes at the bottom). This design keeps the contents well-insulated, and the heat significantly speeds up organic decomposition.
Tumbler compost bins. Tumblers usually come in two shapes: a drum that sits on a frame with a handle, or a kind of barrel that can be rolled around the garden. This design makes it easy to “turn” your composting (more on that later). However, their size is limited and tumblers can make damp materials clump together, which you don’t want.
Open bins. Open compost bins are often home-made, using corrugated iron or wooden pallets to keep their contents enclosed. This retains some of the heat (particularly for larger piles), helping to speed up the process. With open bins, it’s important to check that your mixture isn’t getting too wet or too dry, depending on the season.
Movable bins. Any type of lightweight compost bin that is easy to lift and stack. This makes it easy to turn the compost inside and move compost from one pile to another.
Stationary bins. Any compost bins that are intended to remain in one place while the compost is being made. Once emptied, you may be able to move them elsewhere (but you may need specialist equipment, depending on their size and material).
Compost heap. A freeform compost pile that isn’t enclosed. This is the cheapest and easiest way to start composting, but needs about a cubic metre to work, and can attract pests.
Choosing the best type of compost bin
When looking through these garden compost bin ideas, you’ll need to figure out which is the most appropriate for your garden. To do this, ask yourself two questions; How much space do you have, and what are you most likely to be composting?
If you’re going to be composting a lot of kitchen scraps, an enclosed bin will be best. Urban homes with little outdoor space (or none at all) should look at worm bins or small tumblers. If you have a bit more space, a larger enclosed bin or tumbler is fine.
Homes with a higher ratio of garden waste and/or much more space will find an open bin or DIY bin/heap much more practical.
Deciding What to Compost
Unfortunately, it’s not quite as easy as throwing all of your rubbish into a pile and waiting for it to transform into soil.
Compost is formed by using the right balance of carbon-based waste and nitrogen-based waste. Starting to sound confusing? Don’t worry. In simpler terms, compostable rubbish is often referred to as “brown” materials and “green” materials. Your compost cocktail needs to be roughly a quarter to a third “green” and two-thirds to three-quarters “brown”.
What can be composted?
As a general rule, if it came from the earth, it can go back into the earth. That means organic, plant-based materials (even processed ones like paper), can go into your composting mix. Animal products, however, cannot. No meat and no dairy.
Brown, carbon-based materials make compost light and fluffy. Common brown materials include:
- Shredded paper (not glossy pages, nothing oil/greasy)
- Sawdust, tree bark
- Corn stalks, straw
- Paper-based coffee filters
- Wood ashes, burned matches
- Paper towels
- Wood chips/wood pellets (use sparingly)
- Cotton and wool rags
- Dryer lint (best from natural fibres)
Green, nitrogen-rich materials include:
- Grass cuttings
- Green leaves and plant matter
- Fruit and vegetable scraps, peels
- Coffee filters, coffee grounds
- Tea leaves
- Seaweed (but rinse saltwater off)
- Animal droppings (herbivores only, not cats or dogs)
What can’t be composted?
Obviously, you can’t compost plastics, metals or other man-made/composite materials. However, there are a few less-obvious things you might be wondering about putting into your composting bin. Here’s a list of common things to avoid, and why:
- Meat, bones or fish scraps (creates smell and attracts pests)
- Dairy products, fats, grease and oils (smells and attracts pests)
- Perennial weeds, diseased plants or infested plants (likely to spread when you lay the compost)
- Banana peel, orange peel (often contains pesticide residues)
- Pet waste including litter (cat and dog feces can contain parasites)
- Coal ashes (can contain harmful materials)
- Garden cuttings with pesticides (kills organisms that enable composting)
Extra composting tips:
- Crushed eggshells are good for composting, but not eggs.
- Sawdust is fine, but scatter it thinly to avoid clumps. Make sure there is no oil residue on it.
- Use materials in various sizes. Small pieces biodegrade quickly, but larger pieces prevent your compost from turning into soup.
- Try to save up a reasonable amount of waste to add in one go – it’s not always easy!
Garden Compost Bin Ideas: Getting the Best Results
The best time to start composting is spring, when there is a variety of garden matter available. Start by putting a thick layer of branches and other wood materials at the bottom of your pile, which will help air circulate evenly and allow for drainage.
Next, you can start regularly adding to your pile. Try to alternate between layers of wet materials (like food scraps, coffee grounds etc.) and dry materials (such as leaves, ashes and straw). It’s okay to begin with roughly even amounts of green and brown composting materials – just avoid letting any one thing dominate the pile. Gradually you want to aim for that 1:4 balance of green and brown materials we looked at earlier.
If you have an open pile, covering it with plastic sheeting or wood panels will help to keep heat and moisture in. As your bin gets full, you’ll notice that it begins to heat up – this is a good sign! After a couple of weeks it will begin to cool down, which is when you will need to turn it.
Compost heaps and open bins can be turned with a large garden fork. Basically, you want to thoroughly mix up the contents, get fresh air into it and check that the pile isn’t too wet or dry. Your compost heap will naturally compact over time, limiting the air flow and causing the decomposition to slow down. Turning your compost keeps it processing quickly.
Once you have a sizable pile, you can add more green and brown materials by mixing them in, rather than adding them in layers. Keep turning your compost every 3-4 weeks.
When is the compost ready?
Compost should look and smell like a rich, fresh soil. It will be very dark brown in colour, crumbly and lightly damp to the touch, with an earthy, natural scent. Leave any parts that haven’t fully decomposed and add them to your next batch.
The time it takes to produce compost depends somewhat on the type of compost bin you have, how regularly you add to it and whether you remember to turn it frequently enough. If you’ve been the perfect composter, your garden compost might be ready in 2-4 months. More likely, it will take 6 months to a year.
Speed up the process by keeping your compost heap covered and insulated. Remember to turn it regularly and look out for signs telling you to adjust the moisture or balance of green/brown materials (more on that in a moment).
Forgetting to turn your compost, adding too many bulky items and leaving your heap too dry or too wet will slow the process down.
What’s wrong with my compost?
Composting can be tricky to get the hang of, but you can often tell if you’re getting it wrong by paying attention to certain signs. If you want to check your compost pile is healthy, take a look at some of the common composting problems below.
There are a lot of flies in my compost heap!
Flies are usually attracted to uncovered kitchen waste and moist environments. Make sure you’re adding vegetable food scraps to the middle of the pile and covering it with garden waste, like grass clippings. Turning the heap to increase airflow and reduce moisture is a good idea too.
My compost is getting slimy and soggy!
It sounds like your compost is getting too much moisture, which is very common during UK winters. Add dry brown waste (absorbent materials like a thin layer of sawdust, shredded cardboard or paper), and cover your heap to protect it from rain.
My compost heap smells!
Compost should smell a bit damp and earthy. If the scent is more pungent, it might because of decomposing food scraps. Be extra mindful not to put meat, poultry or fish into the pile, and cover and new fruit or vegetable waste with leaves, sawdust or grass cuttings. If there’s an ammonia-type smell, balance it with more brown materials, like wood pellets, straw or dry leaves.
Nothing is happening in my compost heap!
When trying to avoid a wet compost heap, it’s possible to go too far. Materials need a bit of moisture in order to break down, so try adding more green materials and even spraying it lightly with water. For larger piles that need a bigger kickstart, look into buying an accelerator.
There are big clumps in my compost!
Small, wet materials – like wet leaves, grass cuttings, sawdust or wood ash – often clump together if they’re thrown into a compost bin all at once. It becomes difficult for air to flow through, and decomposition slows right down. This problem is particularly common in tumbler compost bins. The best solution is to pull them out, break them apart with a garden fork, then reintroduce them with other materials gradually or during the next turn.
There is steam coming off my compost pile!
Excellent! Steam means that lots of microorganisms are at work and the composting process is working properly. Look out for it cooling down again as a sign it needs to be turned.
Is there anything we haven’t covered? Tell us about your composting challenges and successes, and share your garden compost bin ideas in action!