Cornus alba · Shrub
Aphids: Squash by hand or spray with a strong jet of water; introduce ladybirds if infestation persists.
Scale insects: Scrape off manually or treat with horticultural oil during the dormant season.
Slugs and snails: Use beer traps, copper tape barriers, or iron phosphate-based pellets to control populations.
Powdery mildew: Improve air circulation and water at the base; apply a sulphur-based fungicide if severe.
Vine weevil: Apply nematodes to the soil in autumn or use systemic insecticides as a preventative measure.