Volutella Blight Disease of Boxwood

Boxwood branch dieback and leaves turning brown - symptoms of Volutella blight. Photo: Paul Bachi, University of Kentucky Research and Education Center, Bugwood.org

Updated: September 14, 2023

Volutella stem blight or canker of boxwood — Both American and English boxwood are susceptible to Volutella

Key points

Both American and English boxwood are susceptible to this disease caused by the fungi Pseudonectria buxi (formerly Volutella buxi) and Pseudonectria foliicola.
Before new growth appears in the spring, leaves on the tips of infected branches turn red, then bronze and finally yellow. Infected branches die back.
Examination of affected branches reveals loose bark and girdling at varying distances from the tips and discoloration of the wood.
In moist weather the fungus produces salmon pink fruiting bodies on leaves and stems.

Discolored leaves — Note the straw color of affected leaves

Loose bark on affected branches — Stems of infected boxwood

Management

Diseased branches should be pruned out and when the foliage is dry.
An important measure to help prevent and control Volutella is thinning (instead of shearing) boxwood to improve air circulation and light penetration. Thinning is a type of pruning that removes interior stems.
Old fallen leaves and diseased leaves that have accumulated in the crotches of branches in the interior of the plant should be shaken out and removed.
Improve growing conditions, especially to alleviate drought stress.

Related information

Boxwood Blight

Boxwood: Diagnose, Manage, and Prevent Common Problems