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Go Green – Composting

Go Green – Composting

16 September, 2013 by Debbie Brace

On the weekend I decided to prune my over excitable passionfruit vines, however I had nowhere to put the resulting prunings. This inspired me to start composting at home and to write a blog about it.

In Australia, approximately 50% of the rubbish that we put into the everyday mixed waste could actually be used in the garden as compost and mulch. So what is the difference between this organic waste going to the tip and it being turned into compost around the home? In landfills, the organic waste is buried anaerobically (without oxygen) and this results in the production of methane gas. Methane gas has 25 times the global warming potential of carbon dioxide and surprisingly, methane gas production causes over 3% of Australia’s total greenhouse gas emissions annually. Methane gas is not produced during composting because it is an aerobic (with oxygen) system. Therefore by composting we can reduce greenhouse gas emission and have healthier gardens.

What is Composting?

Composting is a natural process which breaks organic matter down into a dark substance. This dark substance is nutrient rich and is known as compost or humus.

Benefits of Composting

There are a number of benefits associated with home composting

  • Improves soil structure and quality
  • Increases soil carbon
  • Decreases greenhouse gas emissions and therefore reduces the effects of climate change
  • Reduces the need for watering, on average by 30%
  • Reduces the amount of waste sent to landfill
  • Helps maintain soil pH
  • Helps to suppress plant diseases
  • Reduces dependency on artificial fertilisers and pesticides
  • Adds essential nutrients like Nitrogen, Potassium and Phosphorus back into the soil

How to Compost

1. Get a composter: you can either purchase a ready to go composter or you can make one yourself using recycled materials such as garden stakes, metal or wooden sheets, wooden or metal pallets, wire, etc.

2. Choose a spot for your composter: pick a spot that is directly on the soil, away from the house/building, in a sunny position and has good drainage. Note – if you choose to use a worm farm instead, ensure that it is placed in a shady area otherwise you will overheat the worms.

3. Start the process: Begin by adding a 10 cm layer of brown materials (see ‘What Can and Cannot be Composted’), then add a thin 1 – 2 cm layer of rich soil or finished compost. Next add a 5 cm layer of green materials (see ‘What Can and Cannot be Composted’). Each time you go to add layers repeat this pattern.

4. Maintenance: Ensure your compost is kept moist (but not wet) and that you turn and mix it weekly to help prevent any odours and to increase aeration.

5. Harvesting: Allow your compost to mature, this will take approximately 3 to 6 months, depending on the type of composter you use (see ‘Types of Composter’). You will know that the compost has matured when it:

  • Smells earthy
  • It no longer heats up after being turned or watered
  • Is a dark brown colour and looks like soil
  • Is crumbly and no longer contains any identifiable items in it

Types of Composter

There are a number of different types of composters that you can use

  • Covered Heap
  • Compost Bin
  • Compost Tumbler
  • Worm Farm
  • Pet poo composter
  • Bokashi Indoor Composter

What Can and Cannot be Composted

Green Brown No
Grass clippings Leaves (brown) Bones˟
Pruning Bark Animal faeces (carnivorous)*
House plants Straw Oil
Fruit and vegetable Woodchips Grease
Onion (not worm farms) Sawdust Fat˟
Kitchen scraps Newspaper (shredded) Meat (including fish) ˟
Bread Paper (shredded) Dairy˟
Egg shells Cardboard (shredded) Weed seeds
Coffee grounds and filters Brush (chopped) Diseased plants
Tea bags and leaves Corn stalks Mature weeds with seeds
Citrus fruit (not worm farms) Paper towel Plastic
Fruit and vegetable peels Tissues Metal
Corn cobs Egg cartons Glass
Cereal Pizza boxes Nappies
Grains Vacuum cleaner dust Chemicals
Pasta Clothes dryer lint
Weeds (no seeds) Hair (both human and animal)
Leaves (green) Sticks
Flowers Twigs
Animal manure (herbivorous)
Old potting mix

 

*Note animal faeces from pets can be composted using a Pet Poo Composter.

˟Note Food scraps such as bones, fat, meat (includes fish) and dairy can be composted using Bokashi Indoor Composter.

Sources and Websites to check out:

There are heaps of websites that are dedicated to composting, here are some for starters:

Affiliations: