Secrets to NZ Composting

Bullet point summary from Eve Balfour's “The Living Soil” devised by the Auckland Humic Club

• Anything less than half a cubic metre is difficult to keep hot
• Ratio of 3-4 vegetation to 1 manure. Mixing it lightly as you fill.
• If manure or soiled bedding not available use blood and bone but only a thin film for every 150 mm of vegetation.
• Sprinkle every 150 mm with a couple of mm of earth mixed with wood ash and limestone
• lightly fork over vegetation and manure
• if half of the vegetation waste is fresh green material no extra watering is required
• if a larger proportion is green succulent t material let it wither then wet it otherwise it will silage
• when the bin is half full make and maintain a ventilation hole down the centre. Either with a crow bar or insert a piece of pipe and remove when complete.
• If it begins to have an unpleasant smell it is too wet. Break it down and rebuild.
• Fermentation will slow down if it is too dry
• After 6 weeks it is ready to move into a second box placing any un-composted material into the centre
• It should be watered during this move but no ventilation hole is required for this ripening stage of 4-6 weeks
• If it is to be stored it is best placed in an open shed and turned from time to time

The two NZ compost bins used at HHF. The front wall of both is made of boards that slide into place for ease of loading and unloading. The timbers are painted with sump oil from time to time to slow rotting. Two large screws are embedded into one narrow edge of these boards to enforce the spacing between boards.