Diagnosing Yellow Blisters on Dracaena 'Janet Craig': Fungus vs. Water Quality

An office Dracaena ‘Janet Craig’ showed yellow blisters on upper leaf surfaces. Not scale, not sticky.

Two Possibilities

1. True blisters (water between leaf layers): Likely fungal. Treat with systemic fungicide from a nursery, or spray Lysol (generic) every 3 days for 2–3 weeks (spray at end of day to minimize odor).
2. Yellow circles on surface: Chemical damage from chlorine/fluoride in tap water. All Dracaenas hate these. Use distilled water or let tap water sit 48 hours before use.

Determine which matches your symptoms and treat accordingly.