China Doll Recurring Black Blisters: Root-Bound in Small Pot + Corynespora Leaf Spot—Repot Larger, Lysol Spray, Strict Drying

Root Cause

20 cm pot is too small for a 1-meter plant → root-bound → susceptible to Corynespora leaf spot (black blisters, black leaves, sticky sap).

Treatment (Same as #26694)

1. Repot into 30 cm pot, replace soil, minimize root disturbance.
2. Water lightly; let top half dry (bamboo skewer).
3. Keep water off foliage; empty saucer 30 min after watering.
4. Spray Lysol twice weekly on all leaf surfaces and soil until problem gone for a month.

Prevents recurrence better than replacing the plant.