â ModerateWhite powdery patches on older mint leaves ïŋ― common in dense, overcrowded, humid patches.
ðĐš
Fungal
Powdery Mildew on Mint Leaves
Commonly affects: Mentha spicata, Mentha piperita (Mint)
A white, powdery coating develops on the upper surface of leaves, usually starting on older growth low in the patch. Affected leaves may curl slightly and eventually yellow and dry out.
Potential Causes
- 1High humidity combined with poor air circulation, especially in dense, overcrowded mint patches
- 2Overhead watering keeping foliage damp for extended periods
- 3Shady, still conditions with limited direct airflow
Solution Steps
- 1Thin overcrowded mint stems to improve airflow through the patch.
- 2Water at the base of the plant rather than overhead, ideally in the morning so any splashed foliage dries quickly.
- 3Remove and dispose of heavily affected leaves rather than composting them.
- 4Apply a potassium bicarbonate or sulphur-based spray at the first sign of white patches.
Prevention Tip
Divide and thin mint patches regularly, since mint's vigorous spreading habit quickly creates the dense, humid conditions powdery mildew needs.
