Fungal & Bacterial Leaf Spot
Dark, water-soaked, or ring-patterned spots on the leaves point to a fungal or bacterial infection rather than a watering or light problem.
Common causes
Wet foliage and poor airflow
Spores and bacteria spread fastest on leaves that stay damp with little air movement. Water at the soil, space plants apart, and improve ventilation.
Contaminated water or tools
Splashing water between plants, or pruning with an unclean blade, can carry infection from one specimen to another. Sterilise tools between plants and avoid overhead watering.
Active infection
Spots that spread or develop a yellow halo need intervention. Remove and discard affected leaves, avoid wetting remaining foliage, and treat with a copper-based fungicide if it continues to spread.