How to Manage Pests

Pests in Gardens and Landscapes

Botrytis blight—Botrytis cinerea

Botrytis blight is a fungus that causes flowers to become spotted or discolored. Buds may rot. Leaves and shoots discolor, wilt, decay, and drop. Gray brown spore masses are diagnostic. Twigs may die back. Flower buds may fail to open. The fungus that causes Botrytis blight is favored by high humidity.


Remove and dispose of fallen leaves and debris around plants. Prune out dying tissue. Avoid overhead watering. Thin the plant canopy to improve air circulation. Provide proper cultural care.

Botrytis cinerea on roses
Botrytis cinerea on roses
Discolored Peaonia sp.leaves
Discolored Peaonia sp. leaves
Gray brown spore masses are diagnostic

Decay and spores of Botrytis cinerea fungus.

Statewide IPM Program, Agriculture and Natural Resources, University of California
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