Key Features
- Leaf spots: concentric rings
- Sunken, blackened stem spots
- Pink spore masses on dead stem
Symptoms
Symptoms of Volutella blight begin as small, dead leaf and stem spots. Leaf spots expand and may kill the entire leaf. Concentric rings can be seen within the leaf spots. Stem spots develop into blackened, sunken, girdling (fully encircling the stem) cankers. Small clumps of white to pink spores develop on canker surfaces when stems are damp or humidity is high.
Biology
Volutella survives on infected stems and fallen plant debris, which are difficult to see and remove due to the dense canopies of boxwood and pachysandra. Spores are splashed to leaves by rain or irrigation water.
Management Recommendations
Remove infected branches (or plants if disease is severe) and all plant debris. Decrease plant stresses due to environment, insect feeding and pathogens, and mechanical injury. Use drip irrigation where possible to reduce leaf wetness. Plant boxwoods and pachysandra in locations that receive adequate sunlight throughout the day.
Effective Pesticides
Active Ingredients include: Chlorothalonil, Copper salts
Resources
- Not satisfied with ID? Contact the Purdue Plant and Pest Diagnostic Lab
- Sign Up for the Purdue Landscape Report
