Imagine there was something you could do which would save you money, reduce harm to the environment and turn a waste product into something which can create lasting benefits for your soil and plants!
There is, and it’s called composting!
Composting is the science and art of taking organic waste (essentially anything which has recently been alive) and turning it into a rich, nutritious soil amendment – compost.
In the process, it diverts food from landfill, reduces harmful emissions, reduces the need for fertilizer and improves the structure and fertility of soil. It also creates a product that you would otherwise need to buy for your garden.
In this guide, we will delve into the world of composting, answering the essential question: what is composting?
We’ll explore the science behind it, its benefits, and how you can make your own compost at home. Throughout this guide, you’ll find links to detailed articles for further reading, enabling you to become a master composter in no time!
Table of Contents
What are the benefits of composting?
It's good for the environment
Composting diverts waste from landfill, where it creates harmful methane emissions which damage the environment.
Compost also stabilizes the nutrients in waste, and reduces the need for fertilizer, which releases harmful substances into our ponds, lakes and rivers.
It helps fixes carbon in the ground, prevents erosion and can help clean contaminated ground (especially when worms are involved!)
It’s good for your soil
Compost delivers some nutrients to plants.
However, its true magic occurs in the soil. Here, it increases both aeration and moisture retention and feeds the microorganisms which have a beneficial relationship with your plants.
Research also shows that compost reduces plant pests and diseases.
It may be good for your health too!
Studies suggest that plants grown in compost are richer in nutrients. Those plants require fewer pesticides, and the reduced need for fertilizers means we have cleaner water. Some research even suggests that compost may help with our mental health!
The science of composting
When you add organic material to a compost bin or pile, microbes start to break it down.
Bacteria usually start the process. If the conditions are right, these bacteria will generate heat. Then bacteria which love heat will join in, breaking down the material more quickly.
After the bacteria have exhausted easily available food, fungi will start to play a bigger role. These fungi are particularly important in breaking down tougher material. They are joined by physical decomposers, such as woodlice and worms.
If the compost heap is low in air, bacteria that don’t like air will do most of the work. This will still make compost, but it will also produce lots of methane, which is bad for the environment.
How do you make compost?
Making compost is very easy. All you need to do is heap material into a pile and you will (eventually!) get compost.
However, if you want to speed the process up, and you want the highest quality result, a little knowledge can really help!
To make compost more quickly, and get better results, you need five things:
- A mixture of high carbon (brown) and high nitrogen (green) materials
- Broken down compost materials
Learn More: The Five Rules of Hot Composting
Compost bin, pile or tumbler?
A compost heap is cheap and easy and is great for larger quantities.
However, a compost bin can help keep the compost structure, while a well-designed bin will also provide aeration and insulation.
Compost tumblers feature a barrel design which makes it easy to turn the compost. However, independent tests by Which! Magazine found that they can take longer to make compost than compost bins.
Aerobic and anaerobic composting methods
Most compost methods can be broken into two types.
- Aerobic (with air) composting: The decomposition of materials is done by microorganisms and physical decomposers which need air.
- Anerobic (without air) composting: The breakdown of materials takes place in an oxygen-deprived environment.
What’s the difference?
Aerobic composting is quicker and produces fewer odors. Anaerobic composting also produces larger amounts of methane, which is worse for the environment.
Here’s some examples of Aerobic and Anaerobic compost methods:
Hot Composting: Rapidly breaks down compost material.
Plastic Bag Composting: Material is added to a bag and sealed.
Cool Composting: This takes longer than hot composting. It may or may not be aerobic.
Compost Tumbler: Compost is turned in a barrel-design to aerate.
Bokashi Bin Composting: Organic waste is pre-composted by effective micro-organisms.
Trench Composting: Waste is buried in ground. Sources are mixed on whether this is aerobic or anaerobic.
Vermicomposting: Composting worms turn organic waste into worm castings.
What can you compost?
Theoretically, you can compost nearly anything that has recently been alive.
However, organic materials should only be tackled by experienced composters with hot compost heaps (or certain anaerobic compost methods).
The table below gives you some examples, of what you can and can’t compost:
|Easy to Compost
(or some anaerobic methods)
What tools do you need to make compost?
You need very few tools to make compost. You need a fork and something to carry the material in, but you probably already have those.
As with every hobby, though, the more interested you get the more tools you can use.
These include a thermometer, an aerator (to put air into the compost) and compost forks (to help you turn compost).
Hopefully, this introduction has given you an overview of what composting is.
Remember, there are many ways to compost, and you can easily pick the ones that suit you and your garden.
You can easily get started with the linked guides here. However, if you want to learn more about composting and stay up to date with our guides, do follow us on Facebook, where we share regular tips and tricks to get faster, better compost!
The composting process can vary from a few weeks to several months or even a year, depending on the materials used, the environment, and the composting method.
Can I compost in any season?
Yes, composting can be done year-round. However, the process slows down in cooler weather and speeds up in warmer temperatures.
A healthy compost pile should not emit a bad smell. If it does, it may be too wet or lacking air. Adding dry, brown materials and turning the pile can help alleviate this problem.
Chopping or shredding the waste into smaller pieces, turning the pile regularly to aerate it, and maintaining a good balance of green and brown materials can all help to speed up composting. See How to Speed Up Compost for more information.
Finished compost is dark, crumbly, and has an earthy smell. It should be hard to distinguish the original materials.
Yes, indoor composting systems such as worm bins or bokashi bins are available for those who don’t have outdoor space.
Maintaining a balanced compost pile and avoiding composting animal products can help deter pests (click the link). If pests become a problem, consider using a compost bin with a lid and a pest-resistant design.
Yes, composting is generally safe as long as you handle materials with care, especially if you’re composting manure.
Compost is rich in organic matter and helps improve soil structure, moisture retention, and microbial activity. It’s benefits are primarily seen over the long term.
Fertilizer primarily provides easily available nutrients to plants, and provide a short term benefit to the plants. However, if overused it can be harmful to soil.
- Composting – Cornell University provides a very comprehensive list of resources and articles on all aspects of composting.
- Composting – Royal Horticultural Society (RHS): Excellent introduction to the essentials of aerobic composting.
- Home Composting – Illustrated PDF by Cornell University illustrating several different composting methods.
- Composting at Home – Overview from the US Environmental Protection Agency: Introduction to composting accompanied by several different home composting methods.