Magnolia Hypoxylon Canker: Stress Management Is Key

Magnolia with Cankers: Hypoxylon Fungus

Cankers under bark with dead limbs = Hypoxylon canker. It's a secondary invader attacking stressed trees (drought, root damage, compaction).

Treatment Focus: Reduce Stress

• Water: 1 inch/week during dry spells (pan method).
• Fertilize: 10-10-10 at 1 lb/inch trunk diameter now and spring.
• Prune: Remove only dead/diseased branches.
• No fungicides—ineffective on cankers.

Prognosis

If stress is relieved, tree may compartmentalize cankers. If canopy continues to thin, removal may be needed. Monitor nearby trees for similar stress.