Composting is essentially recycling organic waste into nutrient-rich soil for growing fruit, veg and flowers. Several different methods of composting cater to specific needs and locations, such as backyard composting, vermicomposting, and bokashi composting.
Hot or cold composting is the most common method for home gardeners, where organic waste is layered in a designated outdoor space, allowing for natural decomposition with the help of microbes, oxygen, and moisture.
Vermicomposting involves using worms to break down organic waste in a contained system, making it suitable for both urban and rural settings.
Bokashi composting is an anaerobic process that relies on adding fermented ‘bokashi’ material, capable of breaking down food waste more rapidly than traditional composting methods.
Each composting method has its advantages and drawbacks, with the choice mainly depending on individual preferences, space availability, and types of waste intended for composting.
By exploring these different methods, we can decide which composting technique best suits our gardens and allotments.
Types of Composting Methods
This section highlights the four popular composting methods: Aerobic Composting, Anaerobic Composting, Vermicomposting, and Bokashi Composting.
Aerobic Composting (Hot Composting)
Aerobic composting is the process of breaking down organic materials in the presence of oxygen. This method relies on microorganisms that require oxygen to decompose organic waste.
The compost pile needs to be turned regularly to ensure proper aeration and encourage the growth of aerobic bacteria. This expedites the decomposition process and results in rich, high-quality compost.
Anaerobic Composting (Cold Composting)
Unlike aerobic composting, anaerobic composting takes place in an oxygen-deprived environment. This method uses different microorganisms that do not require oxygen to break down organic waste.
Anaerobic composting is generally slower than aerobic methods and may produce an unpleasant odour due to the byproducts generated during the process. On the other hand, it requires less maintenance and reduces the production of greenhouse gases.
This is by far the easiest way of composting, just throw all of your garden waste, food scraps, grass clippings etc., into one giant pile and let it compost down into compost! It can just take a while. That is the main drawback.
Vermicomposting, or worm composting, involves using specific types of worms to consume and break down organic waste. The worms eat the organic material and produce nutrient-rich castings, which serve as an excellent soil amendment.
Vermicomposting is a relatively fast and efficient process, prevents foul odours, and is suitable for small-scale, indoor operations.
Bokashi composting is a type of anaerobic composting that uses beneficial microorganisms to ferment organic waste. Those microbes, called Effective Microorganisms (EMOs), are introduced to the waste in the form of bokashi bran.
The process involves layering the waste with bokashi bran in an airtight container, which then ferments for a few weeks. The resulting compost can be mixed with soil or added to a traditional compost pile for further decomposition.
Compost bins are an easy way of composting, you add all your food scraps and garden waste to the bin, and it will turn to compost over time.
This is usually cold composting, as the bins are not large enough to generate enough heat to promote hot composting. However, this is not always true, as insulated compost bins are available to promote hot composting even in small spaces.
The classic allotment favourite is the Dalek compost bin, the nickname coming from its resemblance to the Drs nemesis.
These bins are cheap (you can often get them for free) and don’t take up much room. Many people use them but I much prefer an open pile. The bins have a habit of going slimy and stinky if you don’t keep on top of your materials!
Hot compost bins such as the hotbin are much more expensive but have a lot of advantages of their own. They can make compost in as little as two months and also allow for composting of meat and dairy products, apparently, they can compost entire chicken carcasses!
Choosing the Right Composting Method
Various composting methods are available, and selecting the right one for your specific needs will depend on several factors. Consider these sub-sections when making your decision:
Space and Location
Your available space and location will play a significant role in determining the appropriate composting method. Small gardens or urban settings may benefit from compact methods like vermicomposting or bokashi, while larger gardens and allotments can accommodate more extensive systems like pile composting.
Material and Waste Type
The type of waste materials generated will also influence the choice of composting method. Decomposing food scraps, leaves, grass clippings, and other organic waste may require different methods to ensure proper breakdown.
Hot composting, for example, efficiently handles food scraps and kills any weed seeds, while cool composting works best with garden waste like leaves and grass clippings.
Temperature and Climate
Temperature and climate conditions will impact the decomposition process, and some composting methods are better suited for specific environments. Hot composting methods, which rely on high temperatures, may struggle in cooler climates. Consider insulated or enclosed systems like tumblers or insulated bins in colder regions.
Time and Maintenance
The time and effort you can dedicate to compost maintenance should also factor into your decision. Some composting methods require more monitoring and turning (like hot composting), while others need less maintenance (cold composting or vermicomposting).
Composting Tips and Tricks
Balancing Carbon and Nitrogen
Achieving the right balance of carbon and nitrogen in your compost pile is essential for efficient decomposition. Carbon-rich materials, known as “brown” materials, include dead leaves, paper, and wood. Nitrogen-rich materials, called “green” materials, consist of grass clippings, kitchen scraps, and manure. Mixing these materials in your compost pile to maintain a good balance is recommended.
A great way to mix your greens and browns is layering, also known as the lasagne method. You layer alternate materials, one green layer then one brown, and so on.
Aeration and Ventilation
Proper aeration is key for efficient composting as oxygen is needed for decomposition. To ensure adequate aeration, turn or mix your compost regularly using a fork or a compost tumbler. This helps to break up compacted materials and introduce oxygen into the pile, promoting the growth of beneficial microbes.
More advanced industrial systems involve blowing air into your pile through a series of pipes and fans.
Controlling the moisture level of your compost is also important – for hot composting at least. Compost should have the consistency of a wrung-out sponge. Too much moisture can lead to anaerobic conditions, resulting in odours and slow decomposition. To avoid this, add brown materials such as straw, shredded paper, or dry leaves, to help soak up excess moisture.
Conversely, if your compost pile is too dry, it will decompose slowly. In such cases, you should add water or green materials like kitchen scraps or green leaves to increase moisture.
Monitoring Compost Progress
Keep track of your compost progress to ensure it’s working efficiently. The pile should heat up within a few days, indicating that the decomposition process is taking place. If the temperature drops, you may need to turn the pile or add more green materials to heat it up again. The compost is ready to use when it has a dark, crumbly texture and a pleasant earthy smell.
Benefits of Composting
Composting is an eco-friendly process as it aids in reducing landfill waste, thus lowering methane emissions, which contribute to global warming. By composting organic waste, we can help to reduce waste and create a natural alternative to chemical fertilisers.
Also referred to as “black gold” by gardeners, compost can significantly enhance soil quality. It helps balance soil density, retains moisture and suppresses plant diseases, leading to healthier and more vigorous plant growth. In addition, compost provides essential nutrients to plants and improves soil structure by increasing water retention and air circulation.
Composting not only benefits the environment and agriculture but also offers economic advantages. By converting organic waste into valuable compost, we can make our own great compost (have you seen the price of a bag these days!).