Vinca Minor Dieback: Stem and Branch Rot

Sudden Collapse of Established Periwinkle Groundcover

After 20+ years, a large vinca minor planting died back 98% in spring, with only tiny new sprigs remaining. The pattern suggests Phomopsis stem and branch rot.

Disease Characteristics

• Common in spring with frequent rain/irrigation
• Plants "melt down"—wilting, discolored stems
• Favored by overhead watering and dense growth

Management

• Confirm with lab sample (county Extension office)
• Remove dead material; avoid overhead irrigation
• Apply labeled fungicide (e.g., thiophanate-methyl) if confirmed
• Consider resistant cultivars for replanting