Spongy Wood in Magnolia: Decay and Management

A 25-foot magnolia has an 8-inch diameter area of spongy, light-colored wood around an old pruning wound, extending 6 inches deep. The limb is swollen; a nearby wound is solid. The owner asks if the tree can be saved.

Decay Diagnosis

The spongy wood indicates internal decay caused by fungi or bacteria that entered through the old wound. Decay is slow but progressive and cannot be reversed. It may have already spread into the main trunk.

Prolonging Tree Life

Good fertilization and supplemental watering during dry periods can extend the tree's life for many years. However, the tree will eventually succumb. Monitor for increasing hazard potential (large dead limbs, leaning) and consult an arborist if safety becomes a concern.