Diagnosing Patchy Dieback in Established Vinca Minor Groundcover

Investigating Root Causes

Well-established vinca minor dying in irregular patches across sun and shade suggests root system disruption. Common culprits include root-feeding mammals (voles, moles) and fungal root rots, particularly Pellicularia filamentosa (Vinca canker and dieback).

Confirming Fungal Root Rot

Dig up affected plants and inspect roots. A foul odor, blackened or mushy roots, and lack of fine feeder roots indicate active rot. The fungus persists in soil, making chemical control ineffective.

Management Strategies

Remove and destroy all symptomatic plants, including roots. Avoid replanting vinca in the same area; choose a resistant groundcover alternative. Improve drainage and avoid overhead irrigation to reduce moisture-driven spread. Sanitize tools between beds.