Controlling Rhizoctonia Dieback in Vinca

Vinca (periwinkle) suffering from blackened stems, yellowing then browning leaves in irregular patches likely has Rhizoctonia dieback. This fungal disease thrives when foliage stays wet from rain or irrigation.

Management Strategies

• Keep foliage dry: Avoid overhead watering; use drip irrigation.
• Rely on heat: Hot weather often halts disease progression naturally.
• Optional treatment: Apply Immunox fungicide and a light feeding of 10-10-10 fertilizer if intervention is desired.

Improving air circulation and reducing leaf wetness are the most effective long-term controls.