Composting is nature’s way of breaking down organic matter into rich soil conditioner through a hard-working community of microbes, fungi and invertebrates (including worms).
Composting is a quick-win climate action as it removes organic waste from landfill where it can create methane (which is about 25 times stronger than CO2 as a climate gas). You also get a nutrient and microbial rich soil conditioner that helps grow healthy and productive plants and enables carbon to be stored back into the soil.
There are many different commercial and DIY home composting solutions, so it is important to choose a solution that best fits your lifestyle and can support the level of organic input you generate.
Here is the equipment you will need to start:
*Tumbleweed compost bins and turners are available for purchase at Edendale in The Shop.
There is a simple compost recipe that can help you make beautiful rich compost.
Greens + Browns + Water + Air + Time = Compost
Like all living things, a compost needs food being Greens (Nitrogen rich) and Browns (Carbon rich); water for hydration; and oxygen for breathing. Feeding a compost a diversity of Greens and Browns will result in a rich and nutrient dense soil conditioner. If you are having problems with your compost, think about which ingredient(s) from the recipe might be missing and add them.
Green material have a high ratio of Nitrogen over Carbon and are an important ingredient in the composting process. Chopping up your greens will ensure they are broken down quickly.
Green ingredients that are good to add to a compost include:
Greens to avoid adding include:
Brown materials have a higher ratio of carbon and are usually dried organic material. Browns are an equally important ingredient in a productive compost. Tearing or shredding brown ingredients into smaller parts will speed up the composting process.
Brown ingredients you can add include:
Brown ingredients you should avoid include:
Composts are a community of living, breathing organisms which need moisture to survive. A productive compost will get a lot of its moisture from the fruit and vegetable scraps added but sometimes additional water may be needed. A compost moisture level should be like a damp sponge that a couple of drops of water drop out when squeezed.
The amount of you may need to add will depend on the moisture level of the greens you are adding, the season and the type of compost system. An enclosed plastic bin with a lid will require less water to be added than an open cage type of compost.
Like all living things, compost organisms need oxygen to survive and thrive. The most effective compost microbes will breathe in oxygen and breathe out carbon dioxide as they break down organic material. In the absence of adequate oxygen a different family of microbes enter the process and these often breath out methane which has up to 25 time more climate change potential than carbon dioxide.
Adding air / oxygen to a compost is easy, but often forgotten. Keep a compost screw or garden fork next to your compost to quickly use when you add greens and browns, or aerate at least once a week.
Other useful ingredients to occasionally add to a compost include:
The composting process described on this page is often called a Cold Compost as the internal temperature doesn't get too high and as a result the composting process is slow. An alternative is a hot compost where internal temperatures of the compost can get over 60 degrees and compost is made very quickly.
A Cold Compost is a good system for home composting of kitchen scraps as you can add ingredients as you generate them in the kitchen. A hot compost is made in total in one afternoon therefore requires all the green and brown ingredients to be collected at the same time. This may be a better system if you have lots of green garden waste.
How much fruit and veggie scraps you generate will determine how quickly you fill a compost bin. For some people that may be years as it is breaking down the ingredients as you go. Once your compost bin is full it can take another 3 to 9 months for the compost to mature to the rich dark brown compost so loved by gardeners and plants. It will help if you continue to aerate the compost.
A strong smell indicates that the compost is out of balance and potentially producing methane. This is often due to a problem with the recipe. Identify what ingredient is out of balance and adjust the mix. It could be not enough Browns vs. Greens, too much water or not enough air. Adding course Carbon (small twigs and pruning’s) will also help with aeration.
This can happen if a compost is too dry, doesn’t have enough Greens or isn't aerated enough. Identify what ingredient is out of balance and adjust. Make sure you're adding a good mix of Greens and Browns, turn it over and if it is dry, add more water. Add a high nitrogen ingredient like chicken manure or blood and bone to restart the process.
A diversity of insects and spiders can live in a healthy compost and they all play a role in the process. If you have Vinegar flies (like tiny fruit flies) the mix may be out of balance and too acidic. Adjust the recipe to fix the imbalance and add a couple of handfuls of garden lime to re-balance the pH. Cover the compost with a piece of moistened natural material (cotton, wool, hessian) to reduce access to the compost.
To reduce the risk of rats and mice making a home in the compost, don’t add meat, cheese, breads, pasta as these are a vermin favourite. Place the bin on wire mesh or grating with about 10mm holes to deter mice and rats.
Locate a compost near the kitchen so you’re more likely to regularly add ingredients and check on its health. It can be in the sun or the shade although a position with winter sun will help a compost work faster when it is cold. Access to water for an occasional sprinkle is good.
Organics break down faster when they are smaller. By chopping and shredding Greens and Browns you’re increasing the exposed surface area of the material, improving microbial access to the food and increasing the speed of composting. If a compost is working well the internal temperature will rise, again increasing the speed of composting.
Compost that touch the soil need little additional attention in hot weather as the worm can move back into the soil and microbial life form love a hot compost.
Generally no. If your compost touches the ground, it is usually a build it and they will come and once they have made a home in your compost they will quickly breed up in numbers.
The compost worms you can buy are a specific breed of worm (e.g. red wrigglers, tiger worms) that are used in closed worm farm systems. These worms generally feed on the surface and dont transfer into the garden very well
There are many ways to use your compost.
A hot compost is a composting process that creates compost very quickly. The same recipe of Greens, Browns, Water and Oxygen is used but the compost is created in one go. You therefore have to have all the ingredients on hand at the same time. The temperature of a productive hot compost can get over 60 degrees which will kill a lot of pathogens, seeds, weeds and create compost quickly. A hot compost requires a level of physical activity as it needs to be aerated regularly buy turning it over completely. Hot compost can be a good system if you have a large amount of garden waste (green and brown) to deal with
Deep Green Permaculture has a good article on making hot compost
Edendale regularly runs free introduction to composting workshops. These are suitable for people new to composting, those that have some composting problems or questions about their home composting, or those that are composting curious.
Check out the Edendale Events and Workshops page for details of upcoming workshops.