Salvia nemorosa · Perennial
Powdery mildew: Ensure good air circulation and apply a fungicide if severe; resistant cultivars are preferred.
Vine weevil: Check roots when buying potted plants and use biological nematodes in soil during autumn.
Slugs and snails: Use physical barriers like copper tape or apply iron phosphate-based pellets around plants.
Root rot: Plant in well-drained soil and avoid overwatering; improve drainage with grit if necessary.
Aphids: Spray off with a strong jet of water or introduce natural predators like ladybirds.