Fruitless Mulberry Black Bark: Likely Sooty Canker

The peeling bark with black, powdery residue underneath on your desert fruitless mulberry is classic sooty canker (Hendersonula toruloidea), common on mulberry in hot, dry climates.

Symptoms

• Bark peels, revealing black, sooty spore mass.
• Black dust rubs off on hands.
• Branch dieback, wilting, tree decline.
• Enters through sunburn, wounds, frost cracks.

Control

1. Prune out infected branches 12+ inches below visible canker (winter best).
2. Sterilize tools between cuts (10% bleach).
3. Destroy pruned wood (burn/bury)—spores spread easily.
4. Fungicide: Limited efficacy; thiophanate-methyl may help protect wounds.
5. Prevent sunburn: White trunk wrap or dilute latex paint on young/southwest trunks.

Outlook

Advanced infections on main trunk = tree loss likely. Catch it early on branches. Desert mulberries are short-lived (20–30 years) and prone to this.