Treating Bacterial Blight and Fungal Infection in Staghorn Ferns

A large staghorn ("Nellie") declined after six months in a humid atrium: soggy black base, white spots, new leaves browning and falling. The owner moved it to a drier, airy spot under an oak and asked about organic or copper fungicides.

Diagnosis

Bacterial blight with secondary fungal infection. Copper fungicides may control the fungus and prevent spread, but cannot eradicate bacteria already in the vascular system.

Management

• The new, less humid location may allow recovery.
• If a clean pup (offset) can be separated and remounted, it's a good insurance policy.
• Staghorns are slow and sturdy—even severe infections take a long time to become fatal.

Follow your instinct; the plant may surprise you and fully recover.