Neem oil spray

How it works

Azadirachtin in the oil is an antifeedant and growth disruptor: insects stop eating and fail to moult. It kills slowly over 3-7 days rather than on contact, and the oil film also suppresses mildew spores.

Recipe

5 ml cold-pressed neem oil + 2 ml soft soap (as emulsifier) per 1 litre of lukewarm water. The soap is not optional - oil and water will separate without it. Shake constantly while spraying and use within 8 hours.

How to apply

Spray at dusk, covering both leaf surfaces. Every 7 days while the problem is active, maximum 3-4 sprays in a row before switching to a different mode of action.

Targets — pests

Aphids, Whitefly, Thrips, Young caterpillars, Scale, Spider mite, Leaf miner

Targets — diseases

Powdery mildew

Supplies: Cold-pressed neem oil, Potassium soft soap, 5 L pressure sprayer

Days to harvest after spraying: 3

Best months: not recorded

Cautions

Harmful to bees while wet - apply only at dusk when they have stopped flying, never onto open flowers. Do not combine with sulphur, and leave 3 weeks between the two. Not on plants already stressed by drought.

The thing people get wrong

Neem is not a knockdown spray. If you expect dead aphids in an hour you will call it useless and stop too soon. It works over a week by stopping them feeding and breeding - judge it on day 7, not day 1.