Plant guide:ðŋ Rosemary
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â ModerateFuzzy grey mould on damaged stems ïŋ― thrives in cool, humid, poorly-ventilated conditions.
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Fungal
Grey Mould (Botrytis) on Rosemary
Commonly affects: Salvia rosmarinus (Rosemary)
A fuzzy grey-brown mould develops on stems and foliage, usually starting on damaged, dying, or densely packed growth. Affected sections soften and can collapse if the infection spreads.
Potential Causes
- 1Botrytis cinerea fungus, which thrives in cool, humid conditions with poor airflow
- 2Dense, overcrowded growth trapping moisture around stems
- 3Damaged or dying plant tissue providing an easy entry point for the fungus
Solution Steps
- 1Prune out affected growth promptly, cutting back into clean, healthy wood.
- 2Thin the plant to improve airflow through dense sections.
- 3Move the plant to a sunnier, less humid spot if currently in a shaded, still location.
- 4Avoid overhead watering, which keeps foliage damp longer than necessary.
Prevention Tip
Keep rosemary in full sun with good airflow ïŋ― Botrytis is rare on healthy, well-ventilated plants and typically only takes hold in damp, crowded, shaded conditions.
