Chemical Control Of Anthracnose. Web Blight Outbreaks of web blight or Rhizoctonia aerial blight are seen most often on rooted liners and container-grown dwarf cultivars of Japanese and yaupon holly, though liners of other hollies may also be damaged. In general, holly cultivars with dense canopies that are jammed together are particularly sensitive to web blight. Warm to hot, humid weather patterns are essential for disease development. This disease only occurs on holly in landscapes during periods of unusually hot, wet weather.
Brown spots appear along the margin and base of the leaves.
They rapidly enlarge into irregular brown to black blotches that may encompass the entire leaf. Mats of dead leaves usually cling to the damaged shoots. Web blight on Japanese holly cv 'Helleri'. When possible, space plants to improve air circulation. Avoid overhead watering in late afternoon or early evening.