How to Manage Pests

Pests in Gardens and Landscapes

Collar, foot, root, and crown rots—Phytophthora spp.

Several species of the Phytophthora fungi infect the roots or crowns of landscape plants. Plants wilt and leaves become discolored, stunted, and drop prematurely. Often a vertical streak, stain, or canker becomes visible on infected trunks. A cinnamon brown or dark gray discoloration may be seen beneath the bark. Black or reddish sap may ooze from darkened areas of infected bark. Infected mature plants grow slowly and may gradually decline. Twigs and branches die back and the entire plant can be killed.

Identification | Life cycle


Prepare the site well before planting and provide proper irrigation. In soils that are compacted, drain poorly, or are usually damp, and where Phytophthora root rot is a problem, improve drainage and plant only species believed to be resistant.

For more information, see the Phytophthora Root and Crown Rot Pest Note.

Branch dieback on plant with root rot.
Branch dieback on plant with root rot

Bark cut away reveals dark discoloration.
Bark cut away reveals dark discoloration


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