Green Algae

A yellow-green powdery coating appears on holly trunks and twigs, starting on the north-facing side. Green algae grows in wet or humid conditions but doesn't harm the plant. Improve air circulation through adequate pruning and spacing. The algae is purely cosmetic; no intervention needed unless appearance matters.

Adequate pruning to permit good air circulation. Remove infected material promptly and improve growing conditions to limit pathogen spread. Good sanitation, adequate spacing, and proper irrigation practices reduce disease pressure over time.