Whether you are a keen gardener or someone who simply cares about the environment, composting is the most effective and efficient way of dealing with non-protein based waste from your garden and home. Nature really is the best thing to deal with waste and as long as you introduce the various elements to the matter, you will produce a satisfying quantity of rich compost in a surprising period of time.
In nature, waste material is naturally broken down by weather and other living organisms. It is part of the natural cycle.
What is decomposing?
Decomposing is a number of stages where plant material breaks down. In plant material, the living cell and its component parts and held together within a cell wall. This is what give the plant a rigid structure. It is also held together by liquid holding the cell in tension (sap). This is what keeps leaves and soft stems rigid. Remove this and the plant will start to wilt and soften, leaving the woody structures to hold the plant together. Soft leafed plants such as lettuce will wilt very quickly and will not be able to reinvigorate themselves if left in this state for any amount of time. If this cell wall is broken down then the plant cannot recover. So the lush green leaves seen below rapidly start to decompose if cut from a source of moisture.
As you see, the soft leaves rapidly collapse while the woody stems remain rigid. The chlorophyll in the leaves that give them their green colour also rapidly starts to disappear.
The perfect compost is the correctly balanced mix of materials. I suggest 60/40 split of high nitrogen/calcium and high carbon materials.
Good composting is about getting the mix and the conditions just right
High nitrogen/calcium materials –
Grass cuttings is one of the most common sources but not too much. If you have large lawns, you can quickly build up a very large quantity of cuttings. If these all go onto the heap without a mix of other lower energy materials they will start smell – why? Well read on.
Kitchen waste – This is a great source of compostable material. It doesn’t matter if the vegetables have been cooked or are raw, they all go in. As does tougher looking waste such as citrus skins and brassica & sweet corn cores, however the latter should be smashed to allow the microbes to penetrate the tough dense material.
Hen/ pigeon droppings – this is a great source of nitrogen and other elements for compost, however this may contain bacteria that are harmful to humans, so if you have a source of this and want to add it to your compost heap, wear gloves and avoid breathing in the dust. It also has a tendency to turn your heap more alkaline, so although it is a good activator, it should be avoided if the compost is going to be used around ericaceous plants such as heathers, camellias, azaleas or rhododendrons.
High carbon materials –
Paper and cardboard packaging are excellent for composting although do not just dump the daily papers into the bin as their flatness stops air getting in around the fibres. Egg boxes are great and that packaging you often get from mail order companies that has been made by shredding boxes. There is a feeling of satisfaction in composting shredded invoices and credit card bills! Toilet tissue rolls, cereal boxes are all good sources. I suggest you tear large pieces of cardboard up to help the process – remember the smaller the piece, the greater the surface area ratio, so it will rot faster.
Straw and bracken have virtually no chemical contribution to your compost but they add fibre making the compost friable and light.
Small twigs can be added to the compost heap if you have a chipper. Chippers are wonderful beasts that will break up all small woody prunings and leaves so that the resultant pile can be added to your heap. If it is too woody then it will remain woody for a long time – just look at the forest floor the next time you go for a walk.
Dead leaves – You would think these are a dead cert (sorry about the pun) for the heap, however you need to be a little more selective. Some leaves such as chestnut and plane leaves are very slow to break down. I know, I have a very large chestnut in the garden and the pile of leaves I collected many years ago are still happily staring at me in the woodland garden where they were deposited. Oak and hornbeam also do not make good compost as they are low in calcium. Evergreen leaves are often waxy and resistant to water loss, so are not great in compost heaps, so holly and laurels should be disposed of in other ways.
What else can be put in?
Now here is an area of debate. Many disagree with the detail of what can and what can’t go in but there are some sure bets.
- Egg shells – crush them up
- Cut flowers – cut up
- Tea bags and coffee grounds
- Vacuum cleaner emptyings and floor sweepings – this is made up of bits of ourselves and our pets as well as dead microbes – yum
- Vegetable and fruit waste from the kitchen – peelings, damaged or rotting fruit
- Bread – although not if there is any sign of vermin
- Natural fibre clothes (shredded); hair – if you natural down stuffed pillows you are getting rid of – recycle them
- Grass cuttings
- Prunings – avoid rose leaves with black spot if you are going to apply the compost to a rose bed
- Some hamster or guinea pig bedding and droppings
- Newspapers; cardboard and other non-laminated paper (remember the ratio)
- Wood ash – as long as you haven’t helped the fire start with fire lighters or a dose of 4 star
- Soft and perennials weeds – chopped or broken up – nettles are particularly good if crushed and added to water for a couple of weeks
- Seaweed – only take the dead seaweed that is washed up on the beach. Definitely not the stuff that is connected tot he rocks
- Dairy foods and scrap meat or fish
- Barbecue ash
- Coal ash
- Cat litter
- Dog faeces
- Garden cuttings with transferable disease or infestations
- Poisonous plants
- Seed heads
- Non-biodegradable items such as plastics and metal (yes some people have to be told)
- Invasive weeds such as bindweed; horse’s tail; ground elder
I also suggest you avoid biodegradable plastics such as composting bags. These are designed to break down in municipal composters that work at higher temperatures than you are likely to achieve.
A word about faeces
If you have a source of herbivore faeces, this is a good source of material that has already started down the decomposing process and is high in bacteria. Try to avoid adding too much straw from fresh horse manure as this is slow to decompose. Dried cow and sheep manure is good too but watch adding a lot of poultry or bird manure. This is very high in nitrogen; phosphorus and potassium.
Carnivore faeces can of course decompose the same way but dog; cat and human faeces should be avoided as they can be a health hazard through carrying disease and parasites which can then infect humans. The worse of these is Toxoplasmosis which affects the nervous system – not a good idea.
The Right Conditions
Organisms need moisture. Worms especially hate dry soil and will move away from it. Many microbes and bacteria, essential for the composting process, live in water. So water is key to the success of your compost. However too much water will water log the compost heap and make your decomposing heap become sour and very smelly. Remember, water comes in various forms. Not just from rain or tap water but from some of the material you put on your heap itself. For example material such as grass cuttings contain more than 80% water, so the mix of materials needs to take this into consideration. A balance of wet material with soft dry material is perfect, the best being shredded newspaper, cardboard and most satisfying, bills! Why does too much water make the material smelly? It is the lack of the second essential condition – air.
Why is air so important? Well this is back to the basic process. Composting is an aerobic process. A process that needs air to work effectively. The more the better it is. Starve the decomposing material of oxygen, the process slows down and the bi products of an anaerobic process is hydrogen sulphide and ammonia – thus the smell. So regular turning of the material either with a fork or an expensive tumbler will ensure the break down will be quicker and sweeter.
Selecting the best balance of material to compost is important. You are looking for material that contain several elements but in particular have a balance of the two key ones – Carbon and Nitrogen. Too much of one or the other will effect the efficiency of the compost heap. For example, woody material is high in carbon where our grass cuttings are high in nitrogen. Too much of the latter will rot down too fast and exclude the air and we are back to that problem. A mix of soft green waste and finely chopped woody waste is spot on. A ratio of three parts green to one part woody is commonly recommended.
Our refrigerator is useful for one purpose. Slowing down the decomposing process. The greater the heat (within limits) the more the bacteria will breed and work, so the faster the compost will be produced.
Speeding up the process
Once you have established your compost heap you may want to accelerate the decomposition of the material. This can be done through the addition of a compost activator. These can be purchased at most good garden centres. They are high in nitrogen. However you do not need to spend money of this – OK, you may not like the idea, but you do have regular sources of one of the best activators and it is free of charge. Human urine is high in nitrogen and has addition helpful minerals. This really does work – I’ve been told. If such base methods are a bit too much to handle, then lots of gardeners will grow comfrey purely to break it up and add it tot he compost. You can also add so already rotting manure to continue the process.
So if you get the balance correct, you end up with a wonderful, organic, nutritious additive that will enrich your soil whether you are planting vegetables, shrubs or perennial flowers.
You will have your plants leaping out the ground!