Aphids
Green, black or grey insects of 1–3 mm in clusters on shoot tips, buds and leaf undersides. Leaves curl and become sticky with honeydew, on which black sooty mould may grow.
Aphids multiply very quickly in spring, especially on soft, fast-growing shoots after heavy nitrogen feeding.
What can you do?
- Blast them off with a strong jet of water and repeat every few days.
- Let ladybirds, hoverflies, lacewings and blue tits do the work: they usually arrive within a few weeks.
- Pinch out badly infested shoot tips or rub the aphids off with your fingers.
- If that is not enough, spray with a potassium-soap insecticidal soap, making sure you hit the aphids.
Prevention
Feed moderately so the plant doesn’t make too much soft growth, and grow flowers and keep a wild corner for beneficial insects. Indoors, a regular shower helps.
When to watch out: April–September