Pest and Disease Index
Use this index to connect symptoms with likely causes, better photos, and reputable references. It is not a substitute for a diagnostic lab, especially when a plant may need removal or pesticide treatment.
Fast triage
- Whole plant wilting can indicate water stress, root damage, crown issues, heat, herbicide injury, or severe disease.
- Spots on leaves are not all the same. Note colour, shape, margin, whether leaves yellow/drop, and whether spots appear on canes.
- Distorted new growth can come from RRD, herbicide injury, chilli thrips, mites, aphids, or environmental stress.
- White powdery growth suggests powdery mildew, especially on young leaves, shoots, and buds.
- Orange pustules or dust on leaves/stems suggests rust.
- Ragged leaf skeletonizing often points to rose sawfly larvae.
Common diseases
- Black spot: dark leaf spots, often with yellowing and leaf drop; favored by wet conditions and susceptible cultivars.
- Powdery mildew: white or grey powdery growth, distorted young tissue, and poor bud opening.
- Rust: orange spores or pustules, leaf yellowing, and defoliation on susceptible roses.
- Botrytis blight: fuzzy grey-brown growth, spotted petals, drooping buds, and bud failure during cool moist weather.
- Canker and dieback: discolored sunken cane areas, often entering through wounds or stressed tissue.
- Rose Rosette Disease: systemic viral disease with abnormal shoot clusters, distortion, excessive thorniness, and decline.
Common pests
- Aphids: clusters on soft new growth, sticky honeydew, and distorted tips.
- Sawfly larvae: green larvae on leaf undersides, windowpane feeding, and skeletonised leaves.
- Spider mites: stippling, bronzing, fine webbing, and stress during hot dry conditions.
- Thrips: damaged buds, streaked petals, distorted flowers, and scarring.
- Japanese beetles and rose chafers: chewing damage on flowers and foliage in affected regions.
Good diagnosis photos
Take photos of the whole plant, symptom close-ups, the underside of leaves, canes, buds, flowers, soil/pot area, and surrounding roses. Include location or climate zone if comfortable, watering routine, recent sprays, fertiliser, weather, and how long symptoms have been present.
Sources
Discussion log
Use comments for sourcing notes, corrections, and disputed details.
No comments yet.