How to Manage Pests

Pests in Gardens and Landscapes

Seasonal development and life cycle—Botrytis rot

The fungus that causes gray mold, Botrytis cinerea, survives in decaying plant material in or on the soil and as sclerotia. Botrytis infects primarily through germination of its airborne spores. An injury or dead or dying tissue must be present for the fungus to invade. On lettuce, aging wrapper leaves or older leaves at the bottom of plants are usually first infected. Wrapper leaves often provide entry sites for crown rot. Head rot may develop on sites damaged by aphids or downy mildew or other diseases.

Infection in lettuce crownInfection in lettuce crown

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2017 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.