Worm Farm Troubleshooting

A healthy worm farm is almost odourless and looks after itself, so when something goes wrong it is usually one of a handful of issues with a simple fix. Most trace back to overfeeding, too much moisture, or the bin getting too hot.

Smells and a sour bin

A bad smell means food is rotting faster than the worms can eat it, often with too little air. Stop feeding, mix in dry bedding like shredded paper or cardboard to soak up moisture and add air, and let the worms catch up. A handful of garden lime or crushed eggshell helps if the bin has gone acidic from too much citrus or fruit.

Pests

• Fruit flies: bury food under bedding and do not overfeed exposed scraps
• Ants: usually a sign the bin is too dry, so dampen it and stand legs in water
• Vinegar flies and mould: ease off feeding and add dry bedding
• Rats: keep meat, dairy and fat out entirely and secure the lid

Too wet, too hot, or escaping worms

A soggy bin with liquid pooling needs more dry bedding and a check that the drainage tap is clear, since worms drown in a waterlogged farm. If worms are massing at the lid or trying to leave, conditions inside have turned against them, usually too wet, too acidic, or too hot. In a New Zealand summer an overheating bin in the sun will drive worms out or kill them, so move it into deep shade. Fix the underlying condition and the worms settle straight back down.