Composting is one of those activities that many of would like to do, not only to reduce our environmental footprint but to improve our gardens. However, the pressures of modern life, as well as the diminishing size of urban gardens, have made it more difficult to find the time and space to build the traditional steaming hot compost heap.
The good news is, a host of innovative composting solutions exist so that composting is something everyone can do – regardless of whether you live in a small apartment or a lifestyle block.
Worm farming, or vermicomposting, which utilises earthworms to do the dirty work is an odour-free method of composting your kitchen waste. There are tons of worm farms – from ones you can construct yourself to an off-the-shelf type that can be purchased. Commercially available worm farms usually consist of a series of stackable trays that house the worms and organic material they are eating, with a tray underneath to catch the liquid they produce. This ‘worm liquid’ is a balanced, organic liquid fertiliser that is great for feeding your pot plants and vegetable garden – and it’s free!
If you lack sufficient garden space, a technique known as the Bokashi composting system is suitable. This system uses an air-tight bucket that can be kept in the kitchen odour and insect free. Simply add your scraps to the bucket, compress them, and add a bran preparation which contains particular strains of microbes that grow with minimal oxygen and break down the scraps in a fermentation process. The Bokashi system has a reservoir at the base of the bucket to collect the liquid. Because of its high nutrient and microbe content, this liquid should be diluted before being added to your vegetable garden or pot plants.
If you have a reasonable amount of garden space, various options are available. Burying your scraps straight into a garden bed is a great way to carry out ‘cold composting’, or if you have a shady area you can construct an open compost heap that will gradually break down with the help of earthworms and microbes. This can take between several months to a year depending on the materials used. Be careful to avoid meat scraps that will attract rats and maggots, and exclude perennial weeds like kikuyu to prevent excessive weed growth.
Turning Up the Heat
An alternative to an open compost pile is to make or buy a compost bin that encloses the heap. Look for a bin made from black plastic, as this will absorb the sun’s heat and speed up the composting process. Another way to speed up the composting process is the concept of a ‘hot’ compost heap. The secret to hot composting is to create a pile of organic materials at least a cubic metre in volume with the right balance of nutrient-rich materials such as manure and kitchen scraps, blended with fibrous carbon-rich substances like dead leaves and wood chips. Alternate 10-15cm layers of fibrous materials with 5-10cm of the nutrient-rich materials. Mix this heap once a week to create air flow, which is necessary for the microbes to get to work. Apply a few drops of water if the heap is overly dry.