Dieback of Volutella Blight & Boxwood
A common disease on boxwood is a disease known as Volutella Blight and Dieback. This is caused by the fungi known as Pseudonectria foliicola and P. buxi. These are two fungi that are considered weak pathogens, are always around but do not cause much damage until plants are injured or stressed, they rarely infect healthy plants. The Volutella blight alone does not kill boxwoods, but the loss of branches can severely affect symmetry and ornamental value.
Symptoms and signs
When it’s growing season, the infected branches will show stunted growth that could later turn a gray/green color then usually die off during fall or winter. The infected branches then become a tan or yellow straw colored during springtime, when a closer examination of stems you may see the bar splitting or lines in the soil. This causes branches and dead leaves to accumulate. The wood under the soil can blacken and the bar stems start to become loose. The fungus produces clusters of spores that are a pink color on the lower leaf surfaces, these signs appear as cushions of salmon color masses. Foliar systems may occur during winter that causes the Volutella blight to not show signs of fungal infection, but the plant should produce new leaves in the spring and eventually hide the damaged leaves.
- Choose a well-drained plant site
- Take care to avoid fertilizing after mid-summer
- Irrigate Regularly
- Cut back and prune infected branches
Purdue Landscape Report: https://www.purduelandscapereport.org/article/volutella-blight-and-dieback-of-boxwood// Author: Tom Creswell, 4-22