Composting basics

Setting up

Compost works best when it’s warm so a position with winter sun is useful. In larger gardens a two, three or even four bay system provides an organised space for storing raw materials and turning the heap. Ideally, each bay should hold a cubic meter. Plastic compost bins with lids are a convenient ready-to-go alternative to building your own, offering a tidy option for compact gardens while big enough for successful cold composting. Some have a turning system for easy aeration. Once a bin is full, new materials can’t be added until after the composting process is complete (about 6 months), so a twin pair of bins makes sense.

Sourcing ingredients

A successful compost pile needs both ‘green’ (mainly nitrogen) and ‘brown’ (mainly carbon) matter built up in layers. Start with a brown layer then cover every new layer of green material with another layer of brown. This helps prevent smells and flies. Accessible sources of brown material include shredded cardboard and newspaper. During autumn and winter, get the kids to help gather and stockpile fallen leaves. These are among the richest, most valuable of compost ingredients, and arguably all you need. A sack of untreated sawdust or a bale of straw kept next to the compost heap are other convenient sources of brown material.

Preventing bad smells

The most common cause of a smelly compost heap is anaerobic decomposition due to lack of air or an excess of green material. If the heap gets smelly, add more brown material. Cover the compost heap to keep it moist but not soaking wet.

Dealing with vermin

Meat scraps are best left out of a home composting system, but even in the absence of meat, rats and mice love a good compost heap. They’re particularly partial to pumpkin seeds. Some gardeners employ wire mesh linings to help keep rodents out of compost bins. A concrete base is not recommended as this also blocks the soil microorganisms from getting in and doing their good work. Rodents are said not to like the pickled Bokashi compost.