If you think there’s only one or two types of composting, you might be in for a surprise.
There’s actually dozens of ways you can turn organic waste into a soil amendment so valuable it’s called ‘black gold’.
Each composting method has its pros and cons – and its fans and detractors!
In reality, most methods involve trade-offs.
For example, the Berkeley method is seriously fast – but requires a lot of work. A simple static compost pile is less work – but takes more time.
By understanding the different methods available, you can choose the perfect method for your garden and your needs.
So let’s dig into both the factors you need to consider when choosing a composting method and the different composting options available to you.
Top factors to consider when choosing a compost method
Do you need compost fast or slow?
You are most likely to need compost quickly when you start a new garden.
That’s especially the case if you have poor soil, as compost is one of the best ways to improve soil structure.
However, once you have an established garden and several compost heaps on the go, you might be able to take a more relaxed approach to the composting process.
After all, you’ll still end up with the same amount of compost, even if it takes a bit longer!
Do you have a lot of space or a little bit of space?
Some composting methods require a lot of space – others require very little.
For instance, if you have limited or no garden space, a kitchen worm bin might be a suitable choice
If you have a large garden, you might choose to have a series of compost piles or a three-bin composting system.
Your climate (and local pests!)
Do you live in a hot or cold country?
A hot dry climate can drain moisture from above ground compost heap – so you might want to consider pit or trench composting.
On the other hand, if you live in a wet climate, methods like sheet composting might not be the best as they tend to attract pests such as slugs.
How much energy – and time – do you have?
If you’re young, energetic and have lots of time, you might want to consider the Berkeley method.
If you’re not, then you might want to consider a method that does not involve a lot of turning or a tool like a compost tumbler which makes turning easier.
How much material do you have to compost?
If you have a lot of material to compost, you should consider hot composting, as it rapidly deals with large quantities.
Dig or no-dig?
Some gardeners (myself included) prefer a no-dig method of gardening, which avoids disturbing the complex interplay of microorganisms and fungi in the ground.
Depending on how strict you are about no-dig, it can rule out methods such as pit or trench composting.
Are you purely composting for your garden or do you also want to do your bit for the environment?
If you want to help the environment, then you should choose an aerobic method of composting!
Aerobic (with air) is a way of composting that uses microorganisms that require oxygen to break down compost material.
These still produce emissions, but they are less harmful than those made when organic material decomposes in a landfill.
Anaerobic (without air) composting utilizes bacteria that don’t need oxygen.
However, these bacteria also produce methane, which scientists estimates is about 30 times worse for the environment than carbon dioxide.
To minimize harm to the environment, it’s best to mostly use aerobic forms of composting.
Hot composting refers to any method of composting that creates the right conditions for compost to get hot.
The main advantage of hot composting is that the first stage of composting takes place more quickly.
It can also kill most weed seeds and pathogens in a short period of time.
However, in most home composting systems, the compost needs to mature after the hot stage before you use it in your garden.
It’s still an excellent choice if you’re an energetic gardener who needs to generate large amounts of compost quickly
However, some methods of hot composting involve a lot of work. If you’re less energetic, the regular turning of compost may well put you off.
You also need to pay more careful attention to the moisture level and temperature of your compost pile.
Learn how to do it with the Five Rules of Hot Composting.
Not all compost gets hot.
If your compost doesn’t get hot, then you are cool composting.
There may be some benefits to cool composting!
Less nitrogen may be lost (depending on the method and weather), and some research suggests that the finished compost has an increased ability to suppress plant diseases.
This may be because hot composting, while killing pathogens, can also kill the biocontrols which attack plant diseases.
On the other hand, exposure to weather can lead to loss of nutrients.
Cool composting can also take much longer than hot composting – sometimes up to 2 years. In contrast to hot composting, it won’t kill most weed seeds.
(Some sources argue it won’t kill pathogens either, but in fact, at least some pathogens are killed even in cool composting.)
You’re also more likely to end up with brown materials that haven’t fully decomposed.
Read more: Hot v. Cold Composting: Which Is Right For You?
The Indore Method
The Indore Method was developed by Sir Albert Howard in India in the first half of the 19th century.
It originally consisted of alternating layers of animal manures, along with materials such as leaves, brush or straw and chalk or earth on a base of brush.
The material would either be made into a compost pile around 5 feet high or buried in a pit 2-3 feet deep. The pile would be turned twice.
When flies were a problem, the pile would be turned again or covered with a layer of compacted soil.
While the Indore method does involve hot aerobic (with air) composting, it may also involve cool, anaerobic (without air) composting.
Later forms of the Indore method also included human waste.
The Indore method was well suited to the time and location.
For instance, Howard’s method involved leaving tough materials out to be broken up by passing carts.
The essentials of the Indore Method – with modifications – continue to be widely used in parts of Asia.
But there are easier ways to accomplish good compost. Most of us, for example, don’t want to dig a large pit every time we need to make compost!
Some of the advice is also outdated. For example, we now know that we don’t need to add lime in order to make compost.
The Berkeley composting method
Developed at the University of California in the 1950s, the Berkeley method is one of the most famous hot composting methods.
It was designed to maximize heat and speed, with compost being produced in 14-21 days, and is similar to methods used by some commercial composters.
The requirements are fairly onerous, though!
- Compost materials need to be shredded so that the size is between 1/2 to 1-1/2 inches. Woody materials should be put through a shredder.
- The compost heap should have a carbon – nitrogen ratio of 30:1.
- Moisture needs to be maintained at about 50%.
- The height, width and length of the compost heap should each be a minimum of 36 inches (3 feet) to avoid heat loss.
- The pile is built in one go, with nothing added afterward.
- The pile must be turned regularly to avoid overheating, with the outside of the pile being turned into the inside.
For more information see the University of California’s guide to the Berkeley method.
Even if using this method, the compost heap will still benefit from being left to mature – and the attention of worms – after the hot stage is complete.
Insulated hot bins
Insulated bins such as the HotBin (HotBin review here) and the Green Johanna make use of insulating materials to increase the heat and speed of composting without the need for turning.
They are designed to encourage air flow, but you’ll also need to add material to create airspaces inside the composting.
These can’t deal with the same quantities as the Berkeley methods, and take a bit longer to finish composting.
They can, however, achieve temperatures hot enough to kill pathogens and weed seeds.
They also allow you to add compost material in batches, rather than having to add it all in one go.
To create a static pile, you pile up compost and leave it until it’s ready.
These piles can be cool, and take years to be ready.
However, it doesn’t always have to be this way!
Joseph Jenkins, author of the Humanure handbook, is a big critic of turning methods.
He achieves hot compost by doing the following:
- Ensuring the compost is contained on each side, for example with wire or wood.
- Incorporating bulking agents such as weeds and straw in order to trap air in the compost.
- Putting a thick level of cover material, such as straw or manure, under, around and over the pile.
- When adding material, digging a hole, tipping the material in, and covering it back up again.
In addition, you also need to ensure you include a balance of green (high nitrogen) and brown (high carbon) materials in your compost pile.
Limited turn composting
You don’t need to choose between regular turning and no turning.
Limited-turn composting involves creating a compost pile (or multi-bin system), and then turning it one or more times.
Charles Dowding, for example, turns his compost once to aerate it and also to check to see how dry the interior is inside. (If it is dry, he adds water to it.)
I also turn my compost once or twice (using a three-bin method) when composting larger amounts of material, and I find it offers a great compromise between speed and economy of effort.
The Berkely method takes a huge amount of work, while cold composting can take a long time.
Compost tumblers aim to solve this problem for you by making the effort – specifically the turning – a lot easier.
They are usually in the form of a barrel mounted on a stand, with a handle to turn them.
Some forms are also designed to be rolled along the grass.
It will likely take you a little longer to make compost with a tumbler than a system in which you fork your compost over.
A Which Magazine report found:
- A compost bin, forked over weekly, took ten weeks to produce compost.
- A compost tumbler took fourteen weeks to produce compost.
- A compost bin that wasn’t forked over took four months longer than a compost tumbler.
The Which report also found that compost tumblers became harder to turn as the composting process continued.
Pit and trench composting
At its simplest, pit or trench composting involves digging a hole in your soil, placing material in it and covering it with soil.
The soil stops any odors from escaping, and soil microorganisms and decomposers will turn your food scraps into nutrients for plants.
You can then plant on top of the site the next year.
This is one of the simplest methods of composting.
In the UK trench composting is a popular way to prepare the ground for next year’s runner beans.
Pit composting is also a great option if you live in areas where (above-ground) composting is restricted and in hot dry countries where water loss is a problem.
The main thing you need to be aware of is the need to dig a hole deep enough that the materials will not attract predators.
If you are adding 6 inches of food, consider making the hole at least 12 inches deep, and covering it with 6 inches of soil.
Inckel et al, in The Preparation and Use of Compost, describe a process where three pits are dug. The compost is then turned from one pit into another.
In this process, the pit is not necessarily covered over. Water loss can be further prevented with the addition of clay at the bottom of the pit.
There are some drawbacks to the method.
Digging disturbs the soil, damaging the network of Mycorrhizal fungi that carry huge benefits for plants.
Covering the material with soil may lead to anaerobic composting, which releases methane rather than oxygen into the air.
It is also more difficult to follow the progress of the compost than with dry compost.
Despite these drawbacks, in my experience trench composting gives great results.
If you’re interested in this method, check out our guide Six Trench Composting Methods.
Plastic Bag Composting
Plastic (or garbage) bag composting is one of the easiest ways you can make compost.
All you need is a couple of plastic sacks.
Add a mixture of green and brown materials to the sack, soak the material and tie the bag up.
Place that in a second plastic bag and leave for anything from several months to a year.
There are some cons as well as some pros to using this method, so do check out our detailed guide to garbage bag composting before trying it out!
Movable compost pile
Your compost heaps have immense benefit for the soil under and around them. Nutrients leach out of the compost pile, improving the soil.
The shifting compost pile technique aims to take advantage of this, leaving rich ground in its wake as it moves round the garden.
To put in place, simply build a compost pile in part of your garden.
This can be on bare earth, or on top of weeds you want to smother.
After a few weeks, turn the compost, exposing the enriched soil. When the compost is finished, it can simply be spread around instead of needing to be wheelbarrowed to the vegetable garden.
The Rodale Book of Composting describes a variation on this used for raised beds.
The soil is removed from one side of the raised garden.
A temporary structure is built with breeze blocks and the compost built until it reaches four feet high.
When the compost is finished, the compost is removed to enrich the raised bed and the structure is moved along the raised bed.
African keyhole gardens
African keyhole gardens are a form of composting that combines a small, often circular, raised vegetable bed with a compost bin or pile.
The bed contains a gap or ‘key hole’ which allows access through the bed to the compost bin.
Keyhole gardens were developed in Lesotho, Africa for intensive vegetable production.
You don’t have to be in Africa to use the method, though, and they are a neat way to embed composting into a raised bed.
You can construct the gardens from leftover materials such as stones or bricks, which help retain heat at night time, while the bin is often made from woven sticks.
These keyhole gardens have two big benefits.
- They minimize work, as you don’t need to transport the compost around the garden.
- They allow you to benefit from any nutrient run-off from the compost.
Hügelkultur (pronounced hoo-gun-culture) uses rotten wood as the basis for a no-dig raised bed, with a mound of rotting compost on top.
The raised beds are usually in the form of mounds.
While there are variations on how the mounds are constructed, a typical format might be as follows:
- Place large logs at the bottom of a mound.
- Cover with branches, sticks, brush and twigs.
- Add grass, newspaper, cardboard e.t.c. depending on what you have available.
- Put a layer of manure or compost on.
- Finally, add a layer of soil.
They are a lot of work to build, but have some serious benefits.
- As wood breaks down over a very long time, the system can carry on producing nutrients for 20 years or more after it has been created.
- Hugelkultur can also generate internal heat which keeps plants warm.
- The system retains moisture, helping plants to weather droughts.
- As the wood breaks down, it creates air pockets, aerating the soil.
However, it can take a year or two to start seeing the benefits, as the wood can steal nitrogen from the soil in the early stages of the process.You can read more about hügelkultur on Permaculture.co.uk.
Sheet, Blanket or Lasagna Composting
If you want to sheet compost, you simply cover your soil with a layer of organic material and allow it to rot down over time.
You may wish to start with a layer of compost to further suppress weeds.
Then simply spread organic materials such as grass or leaves (or, ideally, both).
A variation of sheet composting was popularised by Ruth Stout in the 1950s.
Ruth used a thick layer of straw to cover the ground.
The straw smothered the weeds, and when new weeds appeared she simply covered them with more straw. She then pulled the straw back when it come to planting.
There are several advantages; turning compost piles, hoeing and weeding are virtually eliminated.
You can see Ruth describing her gardening method in the video below.
However, my experiments in wetter climates have thrown up a few problems.
Grass rapidly becomes a wet mess which prevents oxygen from getting to the soil. Slugs and snails also find the grass a welcome refuge.
The system does work with (unwashed) seaweed, as the slugs hate the salt!
Windrow composting consists of elongated piles of compost. These can be any length, although the height and width needs to be more carefully considered.
Windrow composting is usually used for large scale and commercial composting.
Windrows may be turned to aerate them, or left static, although Leslie Cooperband, in the Science and Art of Composting, say these often go anaerobic in the centre.
Windrows may also use a system of pipes to allow oxygen to circulate through the compost, a process known as ‘passive aeration’.
You can learn more about them, and other large-scale methods, in our introduction to commercial composting technologies.
There are other forms of breaking down organic material that are not strictly composting.
Some of these do not produce finished compost while others produce a valuable soil amendment.
While often called composting, both the process and the result can be quite different.
Bokashi Bin Composting
Bokashi bins are an anaerobic (without air) composting system which use essential micro-organisms (EM) to break down food scraps in an air-tight container.
The EM are held in a bran, which you add to food scraps.
You press the food down to expel oxygen and seal the box to allow anaerobic (without air) fermenting to take place.
However, the name Bokashi Bin Composting is actually a misnomer.
The system produces pre-compost, not compost.
This pre-compost can then be added to a compost heap or dug into the ground.
Liquid is also produced through the system, which some advocates dilute and use as a compost tea.
Learn more about Bokashi Bins.
Vermiculture (worm composting)
Not all worms will do the job, so vermicomposting systems use specific worms such as the red wriggler (Eisena Fetida).
Vermiculture is also known as vermicomposting. However, there is some debate over the names.
In his book The Humanure Handbook Joseph Jenkins argues that because food scraps are digested by the worm, and produce worm castings, the process shouldn’t be called composting at all.
However, it’s worth noting that bacteria are likely to assist in the breakdown of organic material.
And, as we explored in The Science of Compost, worms also play a major role in traditional composting practices.
Still, there are some benefits to using a worm bin.
Your worms will be quite happy living in a shallow container, and they reproduce quickly too.
They also eat a lot!
That means a small bin can usually deal with the food of a family of four without a problem.
This makes the system excellent if you have limited space.
You can even use it in your kitchen and, as long as you maintain your bin properly, you won’t have any problems with odour.
What’s more, one study conducted in India found that worms produced a higher quality compost than other forms of composting.
As for drawbacks, the obvious one is that not everyone can tolerate worms, whether in their house or not.
Most worm bins are limited in size, so are not suitable for dealing with large amounts of waste.
There’s no one right or wrong way of making compost.
Instead, you should choose the right method for your needs and location.
Your needs may vary, too!
For example, in the summer, you may use a hot composting system, but in a cold country, you might want to use plastic bag composting in the winter.
I hope that you, like me, have fun experimenting with different methods until you find the one that works best for you.
Don’t forget that if you want to keep up with different composting methods, and how to use each one, you can follow us on Facebook here!
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