Armillaria root rot

Armillaria root disease comes from fungi in the genus Armillaria. Wisconsin Extension says the fungi make tough, cord-like strands that grow from decaying stumps and roots through the soil. Strands can infect other trees or shrubs through intact roots. Honey-colored mushrooms may appear near the base of an affected plant in late summer or early fall.

The same source says trees and shrubs stressed by drought or defoliation can be especially open to the disease. This page does not diagnose any tree. If a tree or shrub is dying, ask an arborist to look at it. Questions about replanting where a tree stood are covered in the guide on planting a tree after stump grinding.