How to Manage Pests

Pests in Gardens and Landscapes

Pest identification and confirmation—Crown gall

The crown gall bacteria stimulate the plant to produce actively growing, disorganized tissue, which originates in the cambium and appears on bark. The surface of a crown gall is the same color as healthy bark and gall wood has the same color as normal wood. However, when cut with a knife, crown galls are softer than normal wood and lack the typical pattern of annual growth rings. Galls can be tiny and smooth on young plants, but are commonly rough and sometimes massive on mature trees.

Warty tumor of crown gallWarty tumor of crown gall

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