Wood ash

How it works

Potassium and calcium from clean untreated wood, and it raises soil pH.

Recipe

A light handful per square metre, or a dry ring around a plant as a temporary slug barrier.

How to apply

Apply in late winter around fruit trees, gooseberries and currants. Store bone dry - wet ash loses its potassium instantly.

Targets — pests

Slugs (dry barrier)

Targets — diseases

Not recorded — the field is blank rather than guessed.

Supplies: Wood ash

Days to harvest after spraying: 0

Best months: January, February, December

Cautions

Never near blueberries, camellias, azaleas or potatoes: it raises pH and potatoes get scab. Never use ash from treated, painted or coal-burnt wood.

The thing people get wrong

Ash is far more alkaline than people expect - a heavy hand can push a bed out of range for years. Half a bucket per year across a whole garden is plenty, and it belongs around the fruit, never around the acid-lovers.