Decay Fungus on Mulberry: Management for Longevity

What You're Seeing

The white-to-brown, mushroom-like growth at the base is the fruiting body (conk) of a wood-decay fungus. The fungus entered through a past wound and is slowly decaying interior heartwood.

What It Means

• Not an immediate killer. Decay fungi don't attack living tissue.
• Long-term structural risk. Over many years, trunk weakens; large hollow limbs may break first.
• No eradication. Fungus is inside; conks are just "flowers." Removing conks doesn't stop decay.

Management to Extend Life

• Fertilize: 10-10-10 at 1 lb/inch trunk diameter in early spring, watered in.
• Water: 1 inch/week during dry spells (pan method).
• Monitor: Watch for large dead limbs, hollow stubs in crown.
• Arborist evaluation: If near structures, have a certified arborist assess risk annually.

Outlook

With good care, the tree can live decades more. Prioritize vitality—healthy trees compartmentalize decay better.