Encourage predators

How it works

A single hoverfly larva eats around 400 aphids before it pupates, and a ladybird several thousand in a season. Parasitic wasps take whitefly and caterpillars. All of them need nectar from tiny open flowers to fuel the adults doing the egg-laying.

Recipe

Let coriander, dill, fennel, carrot or parsley run to flower somewhere permanent. Add phacelia, calendula, alyssum and yarrow. Keep a shallow water dish with stones. Leave a patch of rough grass and hollow stems over winter.

How to apply

Sow flowering strips in spring and again in late summer. Never spray broad-spectrum insecticide anywhere near them.

Targets — pests

Aphids, Whitefly, Thrips, Caterpillars, Scale

Targets — diseases

Not recorded — the field is blank rather than guessed.

Supplies: Phacelia seed, Calendula seed, Umbellifer herbs

Days to harvest after spraying: 0

Best months: March, April, May, August, September

Cautions

Takes 2-3 weeks to build - it is a season-long strategy, not an emergency response.

The thing people get wrong

The counterintuitive truth of pest control: an aphid-free garden has no ladybirds in it, because there is nothing for them to eat. Tolerating the first small aphid colonies is what recruits the predator population that handles the big ones in July. Spray at the first aphid and you sign up for spraying all summer.