Leaf scorch (marginal leaf necrosis)
Sphaerulina azaleae (formerly Septoria azaleae)
7 host plants
Last updated
Viburnum or linden shows marginal leaf browning and necrosis from salt drift, excessive fertilizer, or environmental stress. Herbicide damage is a common cause. Avoid herbicide drift near susceptible plantings, provide proper watering and nutrition, use deep, rich soil, and check for trunk damage. Recovery is slow but steady.
Management depends on catching it early. Scout susceptible plants regularly and remove affected tissue before the pathogen can spread. Improve growing conditions by addressing drainage, spacing, and irrigation practices. For persistent or severe cases, contact your local Master Gardener program or Extension office for treatment options specific to your host plants.
Quick Reference
Management
Cultural Controls
- Do not apply herbicides near susceptible trees or when drift is likely to occur.
- Use special care when applying broadleaf weed killers to turf near ornamental plantings.
- Use a layer of organic mulch over the root zone to retain soil moisture and to moderate soil temperatures.
- Examine trunks for damage from string trimmers, cankers, or other injury.
- Provide proper watering and nutrition.
- Lindens prefer deep, rich, well-drained soils and plenty of water, but extremely wet or waterlogged soils may damage the roots' ability to take up water.