Beginners guide to composting: what is it, and how to do it.

by James Flint on August 06, 2020

What is composting

Composting happens naturally. When organic matter falls on the ground or stays in the soil, it eventually decomposes and enriches the soil. This nutrition will circle back to the plants as they grow. Humans have experimented with fertilizing the soil with composting as early as they started farming. The first written mentions, however, come from around 2300 B.C. from King Sargon’s reign on clay tablets (1).

Gardening, and specifically organic and natural gardening, has been gaining traction over the last few years or decades. People now convert their lawns into gardens. Many people plant veggies on their windows and balconies. Increased interest in gardening causes an increased interest in compost and composting.

Compost has been called black gold in gardening and farming circles. It has many benefits for the health of the soil and the plants, it increases fertility and harvest, and it can even help prevent pests. It is a dark black dirt-like nutrient-rich soil amendment that should smell just like forest topsoil, earthy and humid. It should never stink.

By definition, compost is an organic matter that decays and decomposes by mechanical forces as shredding and cutting, along with the chemical and biological transformation. The organic matter transforms continually with the help of insects or worms, but mostly by microorganisms like bacteria. The process is never really complete, the transformation will continue even after we add compost to the soil. 

Aerobic and anaerobic composting processes.

Aerobic composting replicates natural decay, it uses bacteria and oxygen for the chemical and biological transformation. Air circulation and oxygen access have to be ensured to promote this type of process.

This process will produce high temperatures that will kill the pathogens, weeds, and seeds. This process can be rather fast, taking from a few days to 2-3 months, depending on the specific method used and the amounts of waste.

A greenhouse gas carbon dioxide is released during the process, but in low amounts compared to methane produced in anaerobic composting.

Anaerobic composting does not need oxygen to decompose, but it will take a long time. It can take years to decay the materials. Anaerobic composting releases methane into the environment.

Methane is a greenhouse gas 30 times more potent than carbon dioxide (2). Not much heat is generated, so it does not kill pathogens, and it produces a strong odor.

This kind of composting is common in the landfill when enormous quantities of waste are gathered, and no oxygen gets in the lower layers of the pile. This is only one of the reasons why sending food waste (any waste) into landfills is harmful.

Harmful impacts of landfills

Many people think that if they send the food waste into the landfill, it is not a big deal, as it will eventually decompose. The truth is, it is always better to reduce waste sent there to avoid negative environmental impacts. In landfills, methane is released to the atmosphere, the materials will take a long time to decompose, pathogens proliferate in those conditions, and other negative impacts. 

Environmental benefits of home composting

Landfill preservations: As mentioned above, probably the most powerful environmental benefit of composting is considerably decreasing the amount of waste sent to landfills. Most garden and kitchen waste can be composted, and that will reduce your trash in around 50-70%. As better waste management processes exist for food and garden waste, we should preserve the landfill space for materials that have no other option.

Fewer fertilizers and pesticides: The compost will serve as a fertilizer in your garden. That will decrease or completely eliminate a need for chemical and synthetic fertilizers and even pesticides that pollute the soil and may negatively impact your long term health.

More carbon sequestering: Using compost as a fertilizer will increase the size and amount of plants that will grow in your garden, more plants will sequester more carbon dioxide from the environment.

Lower carbon footprint of homegrown produce: Fertilized land will produce a higher harvest, which means you will need to buy less produce. Homegrown produce has a much lower carbon footprint, because no transport, packaging was necessary.

Soil preservation: Adding compost the soil will help water retention and consequently decrease the need for additional watering, additionally, it helps to avoid soil erosion.

Home composting methods

Over time, many techniques of home composting have been developed. Here we will mention just the most common and describe them shortly. Most of them work on the same principles, and the process is almost the same. The exceptions are sheet composting, vermicomposting, and bokashi composting that use different methods.

Dig and drop composting (hole composting): Using this method, you build a compost pile directly in the hole dug in the ground. This system does not require any container, just a place where you dig a hole 20 - 50 centimeters deep and as wide as you see fit for your needs. After the hole is ready, you can start composting.

Over the ground composting: Over the ground composting will require a fence or enclosure to hold the compost in place. You can find many options of piles made of wire, or steel mesh, pallets, bricks, concrete, even a cardboard box. The enclosure can be any shape you want. The most common are rectangular and circular shapes.

Composting in a container: You can use a bin to compost your waste. It can be a store-bought compost bin, or any plastic or other container you have handy. There should be holes in it to improve air circulation.

Sheet composting (lasagna gardening): This style of composting is mostly used when you have not enough space to maintain a more traditional compost pile. You will create your compost directly in the place where you will be planting your vegetables.

Create equal layers of organic green and brown materials that will decompose over time. The sheets should be in total around 50 - 60 centimeters high. Be aware of maintaining humidity to aid the decomposition. The layers will shrink down very quickly. Once the material has transformed into a uniform loose compost-like material, you can start planting.

Bokashi composting: This kind of composting was developed by Dr. Teuro Higa in the early 1980s in Japan. It is faster than other methods. The main differences are that bokashi composting is an anaerobic process (no oxygen), and it is fermentation. Bokashi uses an inoculant to aid the process. You can decompose even meat and dairy or other animal products.

Vermicomposting: Vermicomposting is done with the aid of earthworms, most commonly the red wigglers. This requires a container or bin called vermicomposter. Not all the materials that can be composted in compost piles can go into a vermicomposter. The vermicompost cannot reach the same high temperatures to avoid cooking the worms. The result of vermicomposting is called hummus.

How to compost

In this simple guide to composting, we are referring only to the first three methods above.

1. Choose your location

It is indispensable to choose a suitable location in your yard, hopefully, a dry place in the shade with a water supply nearby.

2. Prepare green and brown matter

To properly compost, you will need two kinds of material. Brown material is carbon-rich dry material, and green material is nitrogen-rich material. Brown material can include dried leaves, branches, cardboard, paper, straw, coffee grounds, or sawdust. Green material can be all fresh garden clippings, flowers, green leaves, weeds, fruit and vegetable peels, tea bags, coffee filters, even some stale bread, plain cooked pasta, or wilted flower.

3. Do not compost

Never compost meat and dairy, bones, oils, butter and grease, and cooked foods containing oils, meat, and dairy.

4. Layer the materials

Put the materials on the compost pile in even layers, too much green matter can cause the compost to have a more acidic environment. Keep layering the compost as you generate more waste in your garden at home. For a faster process, chop all the materials into smaller pieces before adding to the compost. This is optional, but it will help you to compost faster.

5. Keep the pile moist

Keep an eye on the humidity of the pile. It should be humid, wet, but not too soggy.

6. Turn the pile

To promote aerobic composting, you need to turn the pile once a week, or at most once in 10 days. You can use a pitchfork, shovel, or another tool you see fit. Make sure air gets to the lowest layers of the pile.

7. Be patient

Keep filling your pile until it gets full, and keep turning it until it’s done. The whole process can take from 2 months to a year or more depending on the conditions. In a hotter climate, it will go faster than when it’s cold. When the compost is full, it will need more time to finish decomposing. You can have 2 parallel piles, while the first one is concluding the natural process, you fill-up the second pile.

8. Enjoy the results

The finished compost looks like loose soil and smells earthy, similar to forest soil. Use it in your garden, give some to your family, friends, and neighbors, and observe how your harvest grows.