Composting takes materials we often consider general waste and produces a material highly valuable for soil.
What is composting?
Composting is the break down (decomposition) of organic material such as food and garden waste by microorganisms in the presence of oxygen, providing a nutrient-dense resource for enhancing soil quality.
Why compost?
- It diverts food waste from landfill or incineration. In landfills, waste breaks down in the absence of oxygen, resulting in the emission of greenhouse gases, carbon dioxide and methane; the latter is 25 times more potent than carbon dioxide. Incinerating food waste can produce energy (relatively inefficient); however, it still contributes to emissions and air pollution.
- It makes a nutrient-rich material that helps with soil structure, moisture levels, pH and disease prevention. How brilliant is waste when it can replenish soil in gardens and vegetable patches?
- It gives you a sense of being in touch with nature and the cycle of life.
- It is easy and free to do.
How to compost at home
To compost at home you need a receptacle, such as a plastic bin (often known as a dalek) or an enclosure of some sort. Ideally, it needs to be placed on bare soil in a convenient part of the garden, preferably where it gets some sun to optimise the decomposition process. Then it’s a case of filling it with waste products from around your home and garden. Appropriate materials fall into two categories:
- Greens – these include fresh materials, such as vegetable peelings, fruit skins, coffee grounds, tea leaves, egg shells and grass clippings.
- Browns – these are dryer materials like shredded paper, cardboard (e.g. toilet rolls), straw (maybe from pet bedding) and dead leaves.
A balance of 50:50 greens to browns is desirable. Overdoing the green material can result in a liquified, smelly mess. Adding too much browns is less problematic. After 9-12 months, the compost is ready for spreading on your garden.
Compost systems
The above compost system is not the only way to compost; there are alternatives:
Hot composting
Unsurprisingly, this is composting at higher temperatures, 40-65°C, resulting in faster degradation and delivering compost material for use in weeks rather than months. A specific hot compost bin or management of materials by mixing and aerating is needed to achieve the higher temperatures. You need to gather more materials at the start for a hot composter than a regular one, and mixing materials before adding to the composter is preferable. This method requires more time and ‘skill’, but benefits from a greater diversity of materials it can incorporate, including:
- Meat and dairy products.
- Dog and cat poo.
- Invasive weeds.
- Small amounts of natural-fibre textiles.
Wormeries
Here, worms chomp their way through food waste and a small amount of garden waste in a wormery (that you can buy). Worms are commonly brandling, manure, red or tiger worms, not the earthworms found in your garden soil. Wormeries often have two compartments; the top is where the worms spend their time with the waste, and the lower area is where the liquid fertilizer collects.
Wormeries generally come with explicit instructions, but in essence, to get started, they need bedding material (supplied with the wormery or old compost), worms and kitchen waste in a similar proportion to the bedding material. They need a location where the temperature is between 18-25°C, and after about a week of settling in, more yummy waste material can be fed to the worms.
Community composting
Community composting is a fabulous idea for people without the ability to compost at home, such as those without a garden and where there is no roadside curb collection through the council for food waste. Minna Alanko-Falola has set up a community composting enterprise in Liverpool, Compost Works, to enable more people to put their food waste to good use. It means more food waste is diverted from landfill and incineration to enrich soils within the community. See her podcast episode on how she got up and running and how it works.
Invest not purge
Composting is one way of putting waste material to good use; it invests in our soils and enables circularity of essential nutrients necessary for us all to survive. It’s quite a fulfilling experience giving back to nature and seems so much more satisfying than throwing waste in the bin.