Recognize indoor fungal diseases and apply the lowest-risk cultural and spray options first.
What they look like
- Powdery mildew: white powdery film on upper/lower leaves; thrives in low airflow.
- Leaf spot complexes: tan/brown disks with darker margins; may show yellow halos.
- Gray mold (Botrytis): fuzzy gray growth on wounds, spent flowers, or dying leaves.
Immediate actions
- Prune infected parts into a bag; sanitize shears between cuts.
- Boost airflow & reduce leaf wetness (water soil, not foliage).
- Consider weekly sprays: copper/sulfur or labeled bio-fungicides; rotate actives.
Prevention
Space plants, thin dense canopies, and water in the morning so leaves dry quickly. Keep humidity moderate and stable.