How to Manage Pests

Pests in Gardens and Landscapes

Deep bark canker—Erwinia rubrifaciens

The symptoms that characterize deep bark canker are the deep cracks running down scaffolds and trunks. A reddish brown to dark brown substance oozes from these cankers from late spring through early fall, giving them a "bleeding" appearance. Internally, dark brown to black streaks of varying width extend through the inner bark and may run for many feet up and down the scaffolds and trunks of affected trees. Numerous small, round, dark-colored spots extend into the wood beneath the cankered areas.

Life cycle


Keep trees healthy by practicing good water management, fertilization, pruning, and pest control. These management practices will also reduce canker development in infected trees and keep them in production in most cases. Only trees growing in poor soils or particularly adverse conditions may never fully recover.

Deep cracks and reddish brown sap
Deep cracks and reddish brown sap

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