WSU Extension


Bacterial blight 
Crown gall 
Powdery mildew 
Euonymus scale 

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Euonymus : Bacterial blight
(revision date: 6/19/2015)

Bacterial blight causes shoots to blacken and die back. Leaf spotting caused by the blight is infrequent on euonymus, but common on other plant species. Infection is favored by moist weather. Wounds are frequent infection sites, especially those caused by frost damage. The bacterium which causes the blight is easily spread by splashing water, wind, insects, and contaminated pruning tools. Bacterial blight is also common on lilac, maple, cherry, and many other woody plants.
Management Options

Non-Chemical Management
  • Avoid overhead irrigation.
  • Prune and destroy infected tissues as soon as they are noticed. Make cuts well below infected tissues and sterilize pruning tools between cuts.
  • Provide proper plant culture. Healthy plants are more resistant to infection.
  • Protect plants from frost damage.
  • Space plants properly and prune to improve air circulation.
  • Avoid wounding plants during periods of moist weather.
Select non-chemical management options as your first choice!

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Bonide Liquid Copper Fungicide Conc/Organic Gardening
    Active ingredient: copper octanoate  |  EPA reg no: 67702-2-4
  • Monterey Liqui-Cop Copper Fungicidal Garden Spray
    Active ingredient: copper-ammonia complex  |  EPA reg no: 54705-7
  • This list may not include all products registered for this use.

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