Author: Will Mitchell – Certification Europe, Waste Enforcement Officer
Welcome, everybody, to International Compost Awareness Week!!
In case you’re new to the scene:
Composting is the recycling of organic materials, by their natural breakdown, into simpler forms, for re-use as fertiliser!
When I say ‘organic’ here I am referring to carbon based things like plant and animal tissues that are not man made, rather than something being chemical free. Think peels, shells and bones or unfinished scraps from some ungrateful’s dinner plate.
Home composting is all about turning scraps and cuttings into something beneficial that you can use.
FACT: Composting is great.
WHY should you compost?
- Composting reduces the need for landfill by taking material away from the bins. Win!
- Composting can save you money by reducing your bin bills! Sweet!
- Composting reduces your carbon footprint because, in landfill, organics produce greenhouse gases, particularly methane. Big win!
- Compost takes away the need to buy plant fertiliser, because it is fertiliser!
- Composting increases numbers of beneficial organisms in your garden.
- Compost spreading helps retain moisture in the soil and can even suppress weeds, plant diseases and pests!
According to www.mywaste.ie, on average, each Irish household is responsible for 117kg of food waste per year! Organic waste collection tends to be cheaper than general waste so go check that out. If you compost at home though you’ll save even more!
In the Irish example, wastes should be source segregated meaning recyclables, general waste and organic waste should all be placed in different bins. Collectors are obliged to offer organic waste pick-ups and if you have not been offered this service you should make enquiries with your waste services provider as not everything can be composted at home. For a quick look at commercial scale composting, check out this here link: Food Waste – how is it recycled
But how does composting work????
Composting is just allowing nature to work away and letting bacteria and fungi, as well as larger organisms like worms and millipedes, eat what you put in.
Nothing is left to waste in nature and if a material can be broken down for nutrients or energy you can bet that there is a critter close by to do it!
Plants are literally made of the stuff that plants need to grow – obviously. But a plant can’t just take what it requires straight from a peel or dead leaf – instead, some changes need to happen.
Organisms in a compost pile physically chew or chemically digest the materials, breaking them down into simpler compounds. After time and multiple stages of decomposition, the resulting product is simple enough for plants to make use of.
Rates of decomposition depend on a few factors like moisture content, oxygen levels, nutrient balance and temperature.
Everything needs water to function and microbes are no different. If your compost gets too dry then decomposition will slow right down – luckily you can restart things by simply adding water.
Two groups of bacteria that will be gently metabolising your pile are aerobic and anaerobic – those that require lots of oxygen and those that require little or no oxygen. Aerobic ones are faster acting and the best way to promote their activity is by forking through and turning your compost to aerate it.
Nutrient balance is about keeping your carbon to nitrogen ratio around 25 or 30:1.
(Sidenote: I have never paid attention to this and my compost seems grand.)
Too much nitrogen means a sludgy wet pile and too much carbon means dry, slow decomposition. This is also known as the brown green balance. Brown items good for carbon are dry things like wood chips, straw, dried grasses and leaves etc., while green items good for nitrogen are things like fresh grass clippings and kitchen waste. If your pile looks either dry or sludgy, it’s easy to remedy by mixing in either brown or green materials as needed.
Finally, the temperature of the pile will affect rates because microbes have thermal ideals. When your compost pile is new it will not have enough mass to retain heat but as it grows it will warm up and stay warm even when air temperatures drop. If you have a large pile or one that gets a lot of sun you may have to toss the material to make sure that temperatures don’t start to kill off the desired microbes!
What are the steps to start composting at home?
Now let’s get talking about how difficult it is for you to start composting at home….
…It’s so easy.
All you need is organic matter and time!
Step 1. Figure out what you want and need depending on your available space and the waste you produce.
If you have a large garden space available and find you have bajillions of food waste as well as grass cuttings and leaves then you might be best to make your own container with some old pallets or sheet metal like in the image below:
OK, that one is fair huge, but it gives you the idea.
From there, you have options all the way down the size scale and it’s just a matter of picking one that fits your space well.
Another thing to consider is placement. Some compost bins have open bases and are best left on top of earth instead of paving, while others, like wormeries, might be designed as separate self contained units. You’re probably not going to want this thing in the middle of your garden, getting in the way of kids games or distracting the eye from your otherwise beautiful domestic vista. However tucking it away in a cold corner mightn’t be great for the process because of those microscopic fusspots, metabolising your scrap stack, downing tools if it’s not warm enough!
Some compost bins are fancier than others. Some have extra insulation and taps or auto-aeration turning premium features. However, they’re all basically big aul tubs for keeping your compost pile together, so don’t stress over this decision.
If you get one with an open base and place it on earth, worms will undoubtedly find their way in. Even if you don’t have one that is specifically labelled as being a wormery you can toss a few worms in and be safe in the knowledge they’ll be like crazy happy in there as long as it doesn’t get too hot.
Once you know what kind of composter you’re getting and where it’s going, comes….
Step 2. Filling it up!
Technically any organic materials will break down over time but that’s not to say that you want to be putting all of them in a pile out the back of your gaf. Fruit, veg and plant cuttings are a perfect place to get you going but for a good long list of what and what not to compost below.
Things that are always good to compost:
● all fruits and veg including peels, rinds, and seeds.
● shells of eggs and nuts
● grass cuttings, leaves and cut or spent flowers.
● rabbit and hamster bedding
● cardboard and paper products like tissues, napkins, newspapers, and coffee filters.
Things you can compost sparingly:
● dairy products like cheeses, butters, or yoghurts as they can create a bad smell and attract undesirable critters.
● woody items like branches or lots of twigs which take a long time to break down.
● fats, oils, and greases which can slow down the process and smell bad.
Things to never compost:
● any metals, glass, foils or plastics (including stickers on fruits) as these will not break down.
● paper products with glossy finishes, paints, or glues
● hard furniture and treated woods
● eggs, meats, and bones will decompose but might cause a foul smell and will attract rodents.
● ashes from coal and charcoal which contain compounds harmful to plants.
● plant cuttings showing signs of disease or mould and plants that have gone to seed as using the compost later on might just spread them
● anything that might have come into contact with herbicides or pesticides because they don’t break down and persist to kill things both in your compost and when spread in your garden.
- Download this handy list of things to compost, never compost or to compost sparingly. Why not print it off and stick it on your fridge or save it on your phone?
I haven’t mentioned a couple of things in the above lists.
Firstly, cooked foods. I tend to leave these out of the compost because I find they go bad quickly and create an unpleasant smell. If I just have a bit of boiled carrot or cabbage I might chuck it in any way, but as a rule, I limit that.
Second up is animal waste. Herbivore droppings should be fine to add to your pile, so you can scoop out your hutches straight onto the compost……..just be careful what you’re scooping out!
Dogs and cats though are omnivores. They have a different gut biota and their excretia harbours some quite harmful microbes.
IF you are dead set on turning your fave pet’s poopies into fertiliser, it is advised that the resulting compost is not used close to any edibles and furthermore it is best to ensure that composts reach temperatures high enough to kill harmful pathogens.
Lastly, I want to mention biodegradable items. This is a bit of an odd one in that biodegrading is exactly what happens in your composter. You might see one of two words on packaging in particular – compostable and biodegradable. Compostable means that you can add it to your home compost and it will degrade and break down like the other things within a specific time-frame. Biodegradable however means that although it will break down it can take a lot longer, like 100 years, and sometimes produces toxins as it does so. You are best to put biodegradable labelled items in your organic bin for collection by the professionals.
Anything that you don’t add to your home compost (that isn’t recyclable or general waste) should be put into the organics bin. The binned organics will also be turned into a nutrient rich compost but on a commercial scale where harmful microbes are managed and tougher materials can be better processed.
For a basic introduction to commercial scale composting, check out this here link: Food Waste – how is it recycled I hope that you’ve been encouraged to boost your composting efforts now!