Primula japonica · Perennial
Leaf spot (Ramularia, Pseudomonas): Remove and destroy infected foliage immediately and improve air circulation around the plant.
Primula rust (Puccinia primulae): Prune out affected leaves as soon as symptoms are noticed to prevent spread.
Slugs and snails: Use physical barriers like copper tape or apply iron phosphate-based pellets around the base.
Vine weevil: Apply systemic insecticides to soil or use biological controls like nematodes in early autumn.
Aphids: Squash by hand or blast off with a strong jet of water; encourage natural predators like ladybirds.