Saving a Peace Lily from Systemic Fungal/Bacterial Infection

Your 11-year-old peace lily "Percival" contracted a devastating infection after exposure to a sick plant. Despite repotting and fungicide treatment, new growth blackens before opening. Here's a comprehensive rescue plan.

Diagnosis: Likely Dual Infection

The symptoms—blackened leaves and flowers, white growth at the base and soil surface—suggest both fungal and bacterial pathogens. The visiting plant was likely overwatered, making it susceptible to infection, which then spread via fungus gnats or proximity.

Immediate Cultural Corrections

• Drastic drying: Let the soil get very dry between waterings—surface dry for 4+ days
• Zero standing water: Empty drain tray 1 hour after every watering
• No fertilizer until recovery is well underway

Dual-Treatment Protocol

1. Switch Fungicides

Your current fungicide treats Phytophthora but not Pythium. Switch to a product labeled for Pythium (common in overwatered peace lilies).

2. Antibacterial Spray (Critical)

Spray the entire plant thoroughly with Lysol-type disinfectant spray:

• Twice weekly for 3 months
• Hold nozzle 12 inches from plant
• Cover fronts and backs of all leaves + soil surface
• Consistency is essential—don't skip treatments

Recovery Timeline

Improvements will be small and gradual. Be patient—plant recovery takes months, not days. If the problem returns, repeat the protocol. But with strict watering discipline, recurrence is unlikely.

Your dedication to Percival is admirable. With this regimen, he has an excellent chance of full recovery.