How to Manage Pests

Pests in Gardens and Landscapes

Armillaria root rot—Armillaria spp.

Cane dieback and wilting are common symptoms of Armillaria root rot. The main roots and crown often have whitish- to cream-colored fan-shaped mycelia just under the bark. Branched black structures, resembling "shoestrings," grow through the soil from roots of infected plants to the healthy roots of neighboring plants. Armillaria sometimes produces mushrooms around the base of infected plants in fall.


The potential for infection by Armillaria can be reduced by the removal and destruction of infected roots or stumps from the soil. It is very difficult to remove all infected wood and roots from the soil, but the progression of the disease can be slowed by this method.

For more information, see the Pest Notes: Armillaria Root Rot.

White, leathery mycelium under the bark
White, leathery mycelium under the bark

Infected root
Infected root (top) with healthy root

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2020 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   Contact webmaster.