Composting and wormeries
At Incredible Edible, we believe in living and working sustainably in a way that benefits our landscapes without harming the environment.
Composting and wormeries are about more than just what we do with our organic waste. Soil is more than a tool for growth and many people argue that the protection of our soil should be placed at the heart of our whole environmental policies. Globally soil is degrading at an alarming rate. Generating three centimetres of top soil takes 1,000 years, and if current rates of degradation continue all of the world’s top soil could be gone within 60 years according to Maria-Helena Semedo from the United Nations.
But at Incredible Edible we don’t focus on what’s wrong; we focus on what’s strong. Our small actions are about more than making great compost they are about being connected to the rest of the world and playing our part in fighting for the future of our planet. When we care for the soil it is an act of resistance and our way to demonstrate local solutions to global problems.
This section helps to get you started on ways that you can connect with the soil and care for it and preserve it for future generations. We may not change the world overnight – but we can change our small patch of it. It may only be a drop in the ocean but at Incredible Edible we believe that the ocean is made up of drops.
How to compost
Just follow the basic guidelines and composting can become a fun and satisfying part of your gardening routine with very little effort.
How does composting happen?
Composting is a completely natural process where organic matter is broken down by bacteria, worms
and a whole host of other creatures. This is nature’s highly effective way of recycling by returning everything back to the earth.
When we heap organic matter together into a bin it creates an environment that accelerates the process and so it decomposes much more quickly.
So how do I start?
After a session of gardening collect all the waste into buckets or barrows and take to the compost bin area. It is important to achieve a balance of nitrogen and carbon, which is much easier than it first sounds.
Plants that are high in nitrogen tend to be sappy, soft and generally green with the exception of flowers,
carrots and parsnips etc.
Plants with high carbon content are quite dry, fibrous and often brown.
Add an equal mix of browns and greens to the bin and you will be well on the way to making good
If you are short of greens add some fruit peels or raw veg waste from the kitchen.
Short of browns? Add scrunched up paper and card.
Need some advice on what kind of bin to use? Read our ‘Tools you’ll need for composting’ advice for further information.
The key to understanding composting is to remember the three basic elements that are needed for composting to happen:
A general rule of thumb is anything that was once a living plant can be composted and the greater the variety of ingredients the better your finished compost will be. Download the ‘What can be composted’ resource for more information.
Easily added by sprinkling a watering can over the bin contents. The moisture content should be like a damp sponge, too dry and composting will slow down. Too wet will cause air to become excluded and create anaerobic conditions and bin will become smelly.
Like us the compost process needs oxygen, this is naturally incorporated as you add to your heap however if the material becomes compacted you can add air by turning your heap. If you are using a dalek style plastic bin add scrunched up paper to the mix as you add the waste, to trap the air between the layers.
How long does it take?
The whole process can take as little as 6 months or up to a year. But when it is finished the compost will look like a rich crumbly dark brown soil with no smell.
Tips to remember
Shredded or chopped material will compost more quickly as this exposes a larger surface area to the bacteria.
Give your bin a water to keep up the moisture levels, this enables the bacteria to work more efficiently and creates the right environment for soft bodied creatures to move around.
Composting activity for children
A great way to introduce the art of composting to children is to take a look at the bug life happening in the bin because it’s like a huge bug hotel of the most productive kind. Have a look at our Composting Safari download.
Dig out some samples of compost and put them on a sheet or on a plastic tray. Have some magnifiers and wooden lolly sticks on hand and take a look through the compost and see what creatures there are and if you recognised them. You can draw pictures of what you see or make notes – use our Composting safari sheet to help you. Use the lolly sticks to push the compost away and the magnifiers to get a really good look at those little creatures.
However caution must be applied too as these are soft bodied creatures which need very careful handling, no prodding allowed and then when the activity is over put the creatures and compost either back in the bin or on the soil.
Tools you’ll need
It is entirely possible to compost without using a bin just by creating a large heap of garden waste in a corner and covering it over with a carpet or plastic sheet leaving it to get on with it.
However most of us prefer a tidier approach by using a compost bin.
Plastic dalek type bins are generally available quite cheaply from your local council or slightly pricier from your local garden centre. Or if you don’t have a budget you could try freecycle.org or gumtree.com. These are perfect for smaller amounts of garden waste although if you have more you can always increase the amount of bins.
Pro’s: easy to maintain, small enough to fit in most gardens, good for small amounts of compostable waste
Con’s: can dry out quickly, the compost can be difficult to access
If you have large amounts of garden waste then you will probably need a box style bin. You can buy ready-made wooden compost bins called New Zealand Boxes or you can quite cheaply build one using old pallets and reclaimed wood. The simplest version is created by just using 3 pallets connected together using screws and wire to form a U-shaped bay and pegging it into the ground using stakes at each corner. To keep the compost material from seeping out of the sides and back, line with wire mesh or carpet. More bays can be added as your needs.
For simple instructions on how to create a compost bay visit www.gardenersworld.com/how-to/diy/how-to-build-a-compost-bin/.
Or construct one from reclaimed or new timber:
Pro’s: compost large amounts of waste, wide opening means easy to fill and easy to access your compost
Con’s: need lots of muscle power to turn those bins
Where to site the bin
This all depends on the space you have available but ideally your bin should be placed on bare ground, in a warm spot and be easy to access. However most gardeners want to grow in the warm sunny spots and the bin is relegated to a much cooler shadier position. This is fine as the waste will still decompose albeit a little slower. Dalek/plastic type bins are best placed out of direct sunlight as it tends to dry them out slowing down the process.
Good pair of secateurs – for cutting up thin branches, tough stems and old brassica’s
Garden fork – helps when mixing to aerate and for turning waste from one bay or bin to another
Water – add a watering can of water for every two buckets full of waste, the contents of the bin should be damp for a speedier process.
Shredder – to shred or not to shred, that is a very good question. Garden shredders are great for breaking down the waste and the smaller the piece of waste is the quicker it will compost. However they are noisy, prone to blocking, and are very expensive. To achieve a similar effect you could try mowing the waste with a manual mower or as above use secateurs.
What can and can’t be composted
An equal mix of greens and browns should give you a problem free bin.
But remember the greater the variety of ingredients you use the more balanced your finished compost will be.
The greens from the garden
- Old bedding plants
- Soft prunings
- Grass cuttings – don’t add in a thick layer, better to add them with brown materials like leaves, hedge trimmings or cardboard
- Weeds: Do not use weeds in seed and avoid pernicious weeds like bindweed, ground elder and docks
- Nettles: Nettles act as a compost accelerator but do not use roots
- Crop debris: Brassicas are tough plants that may need to be chopped or shredded. Also, be aware that old potatoes may sprout in your bin!
- Flower dead heads
From the household
- Fruit skins and cores
- Vegetable peelings
- Tea bags – make sure they are the compostable type
- Coffee grounds
Greens from other sources
- Manure: Be careful not to over manure your heap
- Animal bedding: Only from vegetarian pets i.e. rabbits and guinea pigs
- Seaweed: If you can source it easily and are short of greens for the heap
The browns from the garden
- Twigs/sticks: Will compost more easily if shredded or chopped first
- Fallen/autumn leaves: Mix with grass cuttings to speed up composting or compost alone to make leaf mould
- Bark and shredded wood/sawdust
- Woody/tough shrubs: Will compost more easily if shredded or chopped first
- Hedge trimmings
From the household
- Envelopes – minus the windows
- Scrunched paper: Best to use paper not suitable for recycling
- Wood ash
- Cardboard – i.e. toilet/kitchen rolls, cereal packets
- Hair and nail clippings
- Egg shells – crushed up
What not to compost
As a rule of thumb you can’t compost materials that have never lived e.g plastics and metals. Remember – you need to be mindful that you are creating a resource that benefits the soil and some care is required when adding content to the bin. Here is a list of materials that are high risk for composting but with some added solutions as to what you can do with the offending items.
Persistent weeds – e.g. docks, couch grass, bindweed, ground elder. Do not add to small heaps or dalek bins as they will infect your compost. You can place them in a black plastic bag to exclude all light which will eventually kill them before adding to the bin. It’s also possible to drown them by placing in a hessian sack in a bucket of water, leave for a few weeks, use the water as a plant feed (it will be smelly but full of nutrients), the plant vestiges can then be safely composted.
Weeds in seed – Use the above methods to get rid of weeds in seed
Diseased plants – plants suffering from white rot, club root, blighted potato tubers (blighted leaves can be composted). Also plants that have mildews and moulds that could survive the composting process. Some gardeners suggest you should carefully burn diseased plants.
Coal ash – contains sulphur and large amounts will poison the compost and then your soil.
Cooked food, meat and fish – could attract vermin – see Wormeries for how to deal with composting these types of waste
Dog & cat faeces – These contain parasitic worms.
Man-made fibres – contain chemicals and materials alien to soils, never put in the compost heap.
Metal, plastics, glass – use your local recycling facilities.
If you’re struggling with what’s in your compost bin, here are some commonly asked questions and some great solutions.
My bin is dry and nothing appears to be happening
You have probably got too many dry brown ingredients (slow rotting) in the bin. You need to activate your bin by mixing in some fast rotting “greens”. Good natural activators are grass cuttings (in small quantities), nettles, comfrey and watered down human urine. Moisture is an important factor, ideally your bin should be as damp as a wrung out sponge.
The contents of my bin have become wet, slimy and smells unpleasant
There will be too many “green” (fast rotting) materials in the bin. Mix in some dry “browns” for example leaves, twigs, straw and cardboard. This will absorb some of the moisture and open up the structure to allow some air into the bin.
My bin is attracting flies, what can I do?
These are likely to be fruit flies attracted to the fruit and veg waste in your bin. When adding this type of waste wrap them in paper then bury it into the bin contents or cover it with garden waste and wetted cardboard. By leaving the lid slightly open allows flies to come and go instead of them building up under the lid which can create the cloud of flies when the bin lid is lifted. You can also add lime to make the conditions more alkaline.
Can I put weeds in my compost bin?
Do not add pernicious weeds such as bindweed, ground elder, docks, hogweed etc. Although you can put grassy weeds in as long as they are not in seed. Generally small compost bins do not reach the temperatures needed to kill off weed seeds and pernicious weeds, which is around 60-65 degrees Celsius.
My compost bin is not heating up does this matter?
Do not expect a dalek style plastic bin to heat up as they are too small to generate much heat. However the contents will still compost but more slowly than a hot heap. The process can be helped by keeping the bin in a sunny spot and in the winter you can insulate the bin by putting a layer of carpet on the top. If it’s a box or bay style bin then try turning the heap, if its dry add more greens, water well and cover with carpet.
There are all sorts of insects and bugs in my bin should they be there?
Yes, there is a whole myriad of beneficial creatures that are involved in the composting process. This is the sign of a healthy compost bin so leave them to it!
I have put egg shells in my bin and they don’t appear to be breaking down
When adding eggshells, crush them up first and don’t worry if they are still present in your finished compost, they are biodegradable and will break down in time. The nutrient value is good for the soil.
I’m not very happy with the quality of my compost, it looks rough and woody
Don’t worry, your compost probably won’t look like a commercial product. Its appearance may well be woody. You can always sieve the larger pieces out and put them back through the process. Remember your compost will have a much better nutrient value than shop bought and will be more beneficial for your garden.
Using the finished product
Composting can take between 6 months to a year before you see any results but the wait is worth it.
When the compost is finished it will look rich and crumbly with a sweet earthy smell. You still may find some stubborn bits of waste amongst the compost that has survived the process but just throw those back into the top of the bin to compost some more.
Don’t worry, if you think your compost looks a bit rough, it may not look like shop bought but it will certainly contain all the right plant nutrients and organic matter.
Easy ways to use your compost
The easiest way to use your compost is to use it to top dress beds, borders and pots. Put around 3–5cm of compost around the plants and water. Nutrients from the compost will percolate through the soil to feed your plants.
You can also use a trowel full of compost when planting out your vegetables, herbs and fruit bushes.
Digging the compost into the soil is harder work but can greatly improve the structure of your soil. It will open up a heavy clay soil and improve the drainage. Compost added to a sandy soil can increase its water and nutrient holding capacity also help against soil erosion.
Make potting compost
- Sieve 1/3rd compost finely into a bucket, then sieve 1/3rd garden soil into the same bucket, lastly add 1/3rd gardeners sand mix thoroughly and use.
- Do not be heavy handed with the compost in this recipe as homemade compost is very nutrient rich and will be too strong for your seedling.
- Because of its resistance to pathogens, using your own compost to make potting compost can ward off the fungal disease known as “damping off”.
Wormeries are remarkable for making compost out of kitchen waste.
They not only create a fine textured super rich compost but also a liquid feed which can be drained and collected from the bin.
Brandling worms (Eisenia Fetida) are the stars of the show, they thrive in food waste. Do not be tempted to try and use ordinary earth worms as they would not survive in such a nutrient rich atmosphere. You can find brandling worms in the compost heap usually nearer the bottom but if you want to start a wormery, you will need at least 300 young worms which can thankfully be bought online and usually come ready supplied with any wormery bin you buy.
Where to buy your wormery
How to use your wormery
- Place it in a cool area out of the sun, worms do not like the heat or light
- Start gradually, the food needs to start decomposing in the bin before the worms will be able to eat it
- Slowly add waste food if you add too much, the food will rot and start to smell
- Always leave space for a bedding area with no food in it – they don’t like to sleep in it
- Chop up larger pieces of waste
- Use cooked and raw food
- Feed the worms little and often
What can the worms eat?
- Fruit and veg waste – not citrus fruit, it’s too acidic
- Tea leaves and coffee grounds
- Cooked food scraps
- Meat and fish scraps
- Shredded and torn up paper and card
What the worms don’t eat
- Garden waste and grass cuttings – compost normally in a compost bin
- Bread – goes mouldy
- Onions – too acidic for worms
- If managed properly the bin will not smell however if it does have an odour then check you are not overfeeding as the waste may be going off before the worms can eat it.
In the Winter
Your worms will slow down and eating less so make sure you reduce the amount of food you give them. Shelter the bin if possible in a shed or garage or wrap the bin with a gardening fleece or some bubble wrap.