WSU Extension

Hortsense

Azalea
 
Disease
Botrytis petal blight 
Cylindrocladium blight & root rot 
Leaf and flower gall 
Leaf spot 
Lime-induced chlorosis 
Marginal leaf necrosis 
Nematode (stunt) 
Ovulinia petal blight 
Powdery mildew 
Root rot (Phytophthora) 
Insect
Azalea bark scale 
Azalea lace bug 
Azalea leafminer 
Obliquebanded leafroller 
Root weevils 
Spider mites 



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Caption: Rhododendron marginal leaf necrosis
Photo by: R.S. Byther
  
Azalea : Marginal leaf necrosis
(revision date: 4/23/2014)


Biology
Leaf burn on azalea is a response to stress. Leaves turn brown, especially at the tips and along the edges. Water stress (too much or too little), root or stem damage, excess fertilization, frost damage, and exposure to drying winds are some of the possible causes of leaf burn.
Management Options


Non-Chemical Management
  • Know and follow the cultural requirements for your plant, including proper irrigation and fertilization.
  • Provide adequate soil moisture by irrigation where dry soil is a problem. If boggy conditions are a concern it may be necessary to relocate the plant or use raised beds.
  • Shelter susceptible plants from drying winds and sudden hard frosts.
Select non-chemical management options as your first choice!

Chemical Management

None recommended

Images

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Caption: Rhododendron marginal leaf necrosis
Photo by: R.S. Byther