Aucuba Wilting: Phytophthora Root Rot in Shade Gardens

Blackened, wilting leaves on aucuba indicate Phytophthora root rot, a soil-borne fungus that also affects azaleas and rhododendrons. The pathogen is ubiquitous; disease strikes when plants are stressed by drought, winter injury, or compacted clay.

Management

• Remove wilted branches.
• Improve drainage: amend soil thoroughly with organic matter and expanded shale (PermaTill).
• Replant healthy aucuba in the improved bed.
• No chemical cure exists; prevention via soil health is key.

Images

Healthy plants in well-drained soil resist the disease naturally.