Dogwood: Armillaria root rot

categories: Dogwood Dogwood Diseases Ornamental trees Ornamentals

revision date: 2022-11-22 11:52

White fungal mat of Armillaria root rot infecting trunk.
White fungal mat of Armillaria root rot infecting trunk
Photo by: C.R. Foss


Armillaria root rot is a fungal disease transmitted between plants by root contact. Armillaria is often found in newly cleared soils or ones which have been flooded. Symptoms typically include production of smaller-than-normal leaves, leaf yellowing, leaf drop, and dieback of branches. Symptoms may appear on part or all of the plant. White thread-like masses of the fungus may be found beneath the bark near the crown of infected trees, and/or as shoestring-like rhizomorphs, which are dark strands of the fungus growing on or just beneath the soil surface. Honey-colored mushrooms often grow near the base of infected trees in the fall. Infected trees may also exhibit a dark black line in the infected area encircling the base of the plant.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Remove and destroy infected plants, including roots.
  • Air-dry soil from infected site before replanting.
  • Plant only resistant plants in infected areas.
  • Proper irrigation reduces the likelihood of Armillaria infection.
  • Leave newly cleared ground fallow for one year or longer.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • None recommended

Additional Images