Composting Methods for New Zealand Gardens

There is no single right way to compost, only the method that fits your space, your scraps and how much effort you want to put in. Most New Zealand gardeners settle on one or two of these and let them tick along.

Cold composting

The simplest method: pile garden and kitchen waste in a heap or bin and let it rot down over months. It needs almost no effort, takes longer, and will not get hot enough to kill weed seeds or pathogens. For most backyards with a steady trickle of waste, a cold heap or a basic compost bin is all you ever need.

Hot composting

Build a large heap all at once with the right balance of greens and browns and it heats up, breaking down in weeks rather than months and killing weed seeds and disease. It needs volume, turning and a bit of attention, so it suits gardeners with plenty of material and the energy to manage it.

• Cold heap or bin: easiest, slow, ideal for a steady backyard trickle of waste
• Hot compost: fast and thorough, needs bulk, turning and effort
• Bokashi: ferments all food scraps including meat and dairy in a sealed bucket
• Worm farm: best for kitchen scraps in a small space, gives rich castings

Bokashi and worm farms

Bokashi ferments food scraps, including meat and dairy that normal compost cannot take, in a sealed bucket with an inoculant, after which the pickled waste is dug into the soil to finish. A worm farm handles kitchen scraps in a small footprint and produces concentrated castings and worm tea. Many keepers run a compost bin for garden waste and a worm farm or bokashi for the kitchen, covering everything between them. See the worm farming guide for that side.