Home Composting: A Practical Guide

Home composting turns fruit and vegetable scraps, leaves and other organic matter into compost for use in the garden. The recommended approach is to combine nitrogen-rich “green” materials with carbon-rich “brown” materials, using roughly 2 to 3 parts dry material to 1 part green material, while keeping the mix damp rather than waterlogged.

Why combine green and brown materials?

Green waste, including fruit and vegetable peelings and scraps, mainly supplies nitrogen. Dry leaves, straw, small twigs and other brown materials provide carbon. The micro-organisms that break down the material need both of these nutrients to grow and process the waste.

A ratio of 2 to 3 parts brown material to 1 part green material is a practical guideline for home composting. The precise balance will depend on the ingredients used, but maintaining it matters: too much dry matter can slow decomposition, whereas an excess of wet, nitrogen-rich material may cause odours.

How does moisture affect decomposition?

A compost bin needs water for micro-organisms to do their work, but too much moisture fills the gaps through which oxygen should circulate. The mixture should therefore be damp without becoming saturated. As a practical guide, it should feel like a wrung-out sponge.

If the contents are too dry, add small amounts of water. If they are overly wet, dry leaves, straw or another brown material can be added to absorb some of the moisture and restore the mixture’s structure.

How do you set up a compost bin using household waste?

Choose a container or area with suitable ventilation and, where possible, shelter it from direct rainfall. Begin by layering or mixing fruit and vegetable scraps with dry leaves, straw and small twigs. Larger items can be chopped up to increase their surface area and help them decompose more easily.

As the process continues, monitor the smell, moisture level and appearance of the mixture. In systems that require turning, mixing the contents helps replenish oxygen and spread moisture more evenly. Poor aeration can slow down decomposition and lead to unpleasant odours.

Who can start home composting?

Composting can be carried out in homes with gardens as well as in smaller spaces, using suitable options such as household compost bins and wormeries. The size of the set-up should reflect both the amount of waste produced and the space available.

At first, it is best to use appropriate plant-based materials and avoid waste that may attract pests or pose risks in home systems, such as meat, fish, dairy products and fats. Once the original materials can no longer be identified and the compost is dark and soil-like in appearance, it can be used in the garden according to the system in use.