Salvia rosmarinus · Shrub
Rosemary beetle: Hand-pick beetles and larvae or use a biological control like nematodes.
Powdery mildew: Improve air circulation and spray with a fungicide if severe; avoid wetting foliage.
Root rot: Ensure well-drained soil and avoid overwatering; do not plant in heavy clay without amendment.
Scale insects: Scrape off scales manually or treat with horticultural oil during the dormant season.
Honey fungus: Remove infected plants and surrounding soil; avoid replanting in the same spot for several years.