I was cringing every time I had to throw away a full bowl of peels after preparing a meal – what a waste! At the same time, my plants were longing for some good feed. Finally, Citizen Farms by Edible City Garden had listed a workshop titled “Turning waste into gold: composting & insect farming”. While it wasn’t a hands-on workshop, there was a lot of valuable information provided.
What is composting (from Citizen Farm info sheet)?
Composting is the process of breaking down of organic waste into basic components forming fertiliser. Organic matter like food scraps, leaves, and paper are added to a pile to be broken down by worms, fungi, bacteria or other organisms over a period of weeks or months depending on the type of organic waste and composting method. Water, oxygen and the rights mix of organic materials are essential in this process.
Benefits of compost (from Citizen Farm info sheet).
Composting takes organic waste that would otherwise be incinerated and turns it into a rich source of nutrients that can be used to fertilise and enhance the soil.
Compost adds nutrients and beneficial microbes to create a lasting and healthy soil environment, which is beneficial to the plants and organisms living in it. It also helps to retain water in the soil and can reduce soil erosion.
Did you know? Every ton of compost can sequester half a ton of carbon dioxide – it is one of the cheapest and most efficient ways to protect our environment by storing carbon in the soil in a stable and useful form. In landfills, where there are unfavourable conditions, carbon and methane are released into the atmosphere trapping heat and contributing to climate change.
What to remember for successful compost (from Citizen Farm info sheet)?
Nutrient balance: composting requires a proper balance between “green” organic materials which are rich in nitrogen and “brown” organic materials which are high in carbon. This classification has nothing to do with colour – for example, coffee grounds are green material as they are rich in nitrogen content.
A general rule of thumb:
40 % green – raw food scraps, fresh grass trimmings, grains and nuts, coffee grounds, tea leaves/ tea bags if not from bleached paper, egg shells
60 % brown organic material – required for a balanced feedstock – paper/cardboard, wood chips, dried leaves & branches, wood ash, sawdust.
If you are like me dragging the execution of starting your own compost, because of a worry that it is a demanding task, don’t be. It is REALLY easy! Here is how I started:
I bought a 33.8 L (32 cm diameter, 42 cm height) clear strong plastic bucket with a lid in a wet market. You can buy any size you like, however, it is good to remember that it will become heavy with the growing pile of compost and you will need to lift it, aerate the compost and eventually take out the compost and use it. So before deciding, I would suggest thinking about these and what are you going to do with the amount of compost you will end up with.
Using a drill (no need to buy, you can borrow), I drilled some holes at the bottom – they allow the liquid to drain out of the compost and provide aeration. You will need to use pressure, but avoid the impact of the drill with plastic once the hole is made – the moment plastic gives in and the drill goes in – since it will cause the plastic to crack.
Next, you will need a tray or, as in my case, I found an old wide container such that when inserted the compost bucket fits a few centimetres above the bottom of the container. This way there is an empty space between the compost bucket and the container for liquid to be collected – perfect!
Another very useful point I learnt was to buy good quality ready compost (ensure it doesn’t contain chemicals). I spread a couple of litres at the bottom of the compost bucket. It provides beneficial bacteria, worms’ eggs, all of which speed up the composting process. I will disclose later what additional unexpected guests we had in our compost, but that’s later ☺
We are a 5 people family and we eat a lot of fruits and vegetables. So you can imagine how much organic waste we produce. After we started composting, we realised that at the end of the day our dust bin remained almost empty since we already recycle paper and plastic, this means that majority of our daily waste is organic. Such a pity to send it to incineration! Chopping/shredding the scraps reduces composting time and allows for a more even mixing, which improves pile insulation and maintains optimum composting temperature (not that I’ve ever measured it!). ☺
What to avoid in the compost pile (from Citizen Farm info sheet):
- Diseased plants
- Weeds with seeds and roots
- Dog, cat or human faeces
- Toxic chemicals
- Fat, oils and grease
- Meat scraps (raw or cooked), bones and dairy
- Treated logs (they contain chemicals)
- Garden waste that has been treated with pesticides or chemicals
- Citrus (worms don’t like them) ☺
What to remember (from Citizen Farm info sheet + my insights):
- Microorganisms (i.e. bacteria, fungi, etc) and earthworms living in the compost pile require sufficient water to thrive. This water can come from organic material itself or you can add water, bus also – read this – wine, beer, cider, which provide yeast. Let the worms party a bit ☺
A compost pile with sufficient moisture should feel like well-wrung rag or sponge – just slightly damp.
- Aeration helps to increase the rate of decomposition and reduce bad odours. Indeed, a perfect way to know that your compost is doing well is that it produces no smells! Too much aeration can cause the compost pile to dry out. To increase aeration you can manually turn the compost, add materials like shredded paper (without paint/ink), woodchips and straw.
To reduce aeration and to prevent it from drying, cover the bucket a bit more with a lid. But not too tight or living organisms will start crawling out of the bucket or they will die, poor things.
- Remember that container under the compost bucket? Don’t forget to empty it about once a week as it fills with liquid.
With the size of the bucket I chose, we were able to keep adding scraps to the pile for a good few months. After a few weeks, we also discovered unexpected guests – black soldier fly larvae!
These are very welcome guests because they eat scraps at a rapid pace and within a short period of time, you can see the creation of compost right in front of your eyes. So we made our best to keep them comfortable and happy in our compost bucket. Their lifespan is 7 weeks, so, sure enough, I am now finding empty shells in the pile. Oh well, that’s life!
By the way, in the second image, you see a container that collects the liquid drained from the composting pile and some larvae floating in it (escaped through the holes at the bottom of the bucket).
Don’t forget the layering – one layer of green, covered with a layer of brawn matter.
You know when you are missing brown matter, it is when ants attack your pile. Here are a few tips on how to tackles some of the issues that might arise.
Tips (from Citizen Farm info sheet):
|Pile will not heat up / not composting
|Worms are running away or dying
|Pests (i.e. ants, fruit flies, etc)
- Coffee (ground) can be added to increase acidity, improve drainage and retain water. It also deters harmful pests and encourages earthworms.
- Crushed eggshells add alkalinity
- Earthworms only break down plant-based material; Black soldier flies larvae break down everything.
The process of ageing of the pile:
The first month, we simply added alternating layers of scraps and dry leaves/paper. Last layer should always be brown matter. During the second and third months started mixing about once a week. It’s important that microorganisms will be evenly distributed. We keep our bucket in relative shade, no direct sunlight –as the temperature is an important factor for successful composting.
At some point, at the very bottom of the bucket, we discovered white mushrooms growing. This is a good sign, it means that compost is of high quality.
Start using compost only after about 6 months and don’t use before you can see fungus growing. The texture should be very crumbly, black and no unbroken scraps. That’s it. Happy composting!
Scientist by training Anna Itkin is an analytical and critical thinker with strong ability to think in systems and across disciplines. With unconventional career path, international and cross-cultural life experience she has an edge and see things differently.
Passionate about sustainable development and driven by the vision of systems change she co-founded The Inceptery – sustainability-driven innovation consultancy. They apply design framework to create new streams of value and enable business growth with positive environmental and social impacts. It’s not about tearing down old ideas, it’s about creating new ones.