Ari Merten – Year 12

In its simplest form, composting is the breaking down of organic matter. Organic matter, for the chemists among us, is anything with carbon in it, or really just anything that was once living. Over half of the material thrown out in Australian houses is organic matter and can be reused via composting to create what gardeners call ‘black gold.’ Composting is incredibly useful as it enriches the soil of your garden and reduces the need for store bought fertilisers (which can be expensive and dangerous to other flora and fauna in your garden). Finally, composting reduces methane emissions and lowers your carbon footprint. 

Food in landfills break down in ways that create greenhouse gases which can then affect air quality and public health. By composting we can dispose of our food waste in a much more environmentally friendly and efficient way. Composting your own waste is a great example for your community and will have an impact on the environment. A little goes a long way!

There are three main different methods of composting:

1. Worm farming: This creates a liquid fertiliser
2. A compost bin: This either be stationary or tumbling
3. A bokashi bin: a Japanese method for composting meat and fish products

Worm farms are designed mainly for food scraps and aren’t too difficult to set up. The farm can be bought from a variety of hardware stores and worms can be bought from specific worm farm companies (which can be found on various websites). Once you’ve set up your worm farm and lined it with the soil bedding, you should give the worms a week to adapt to their new environment. Once this is done you can feed your worms:  

• Bread
• Egg cartons
• Egg shells
• Fruit and vegetable scraps
• Small amounts of citrus and onions
• Tea leaves and bags
• Moist newspaper
• Vacuum dust!

Unfortunately, you cannot put in dairy, meats, fatty products or oil, but never fear, read on to find ways to compost these items!

After some time, the worms will create worm urine which can be drained from the tap in your farm. This can be used to fertilise grass or any plants in your garden. When the trays of your worm farm become full you can harvest the castings (worm faeces) which are jam-packed full of fertiliser and place it wherever you need in your garden to stimulate growth.

The next method is compost bins which meet a variety of needs. If you like to get down and dirty with your backyard then a compost bin is the way to go. Every 1-2 weeks you need to turn your compost over with a shovel to ensure the waste can decompose and after a few turns of your compost you can use it as fertiliser. A tumbler is a less labour intensive method which is similar to the compost bin except it can spin and turn the compost with less effort. However, with a tumbler composter all you need to do is give it a few turns whenever you place compostable items into it. Depending on how big your tumbler is and how much you put in it can take between a month to a year before you need to harvest. Our school has a compost tumbler that we empty natural waste into twice a week! Another method of composting is to add worms to your compost. This way you don’t have to do any manual labour and can simply put your compostable waste into the bin for the worms to enjoy. 

Like the worm farm, avoid placing meat, bones and fish scraps into your compost bin and instead place them into a bokashi bin! The bokashi bin takes these products and ferments them and you can then bury them in the ground to enrich your soil.

Bokashi bins are really simple to have in your kitchen and are fantastic to compost cooked food and other food scraps that can’t go into your other composting farms. Bokashi bins can be bought at any of the places where you can find compost bins, as well as dedicated online stores. Learn more about bokashi bins here.

They are incredibly simple to use as you simply place all of your food scraps into the bin, either add 2-3 sprays of a liquid bokashi or sprinkle bokashi mix over it and firmly close the lid. This spray or mix is made from natural ingredients and accelerates the fermentation of your compost. These can be purchased from wherever you buy the bokashi. Throughout the day the waste will ferment but not putrefy thanks to the spray/mix. You can regularly tap out of the bottom to get similar fertiliser to that of a worm farm, which can be used to spread over your garden.

It is best to have two bokashi bins as when one is full it still needs time to ferment and you can continue placing your scraps into the second one. The bokashi bin does require a little bit of digging as you need to create a small hole in your garden to place the waste into. Dig the hole, pour the waste in and cover it with some soil and now you’re done! Your soil will become enriched by the nutrients within the waste. If you don’t have room to dig a hole every time your bokashi bin fills up you can use the same spot and when all the waste has broken down you can use it as topsoil. If you can’t dig a hole, another option is to leave it to ferment for a few more weeks and then place it into your compost bin!

Here are some of the things you can put into a bokashi bin:

• Fruit and vegetable scraps
• Citrus
• Meat (raw or cooked)
• Fish (raw or cooked)
• Dairy (not milk)
• Eggs
• Bread
• Tea bags
• Packaged food scraps

If you produce a lot of food waste, but don’t have a garden or can’t compost, read how you can compost with no backyard, particularly the part on council food scrap collections. Making the switch to composting using even one of these methods can make a massive difference to the amount of food you throw out and will have a positive impact on your garden as well!