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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Lilac > Spots or blotches on leaves

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Lilac > Leaves > Spots or blotches on leaves

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  • powderymildew1
  • powderymildew2
  • powderymildew3

Powdery mildew
Microsphaera syringae

  • Leaves have dry, grayish white spots, blotches or are completely covered with white fungal growth
  • Leaves appear dusted with flour
  • New leaves may become distorted
  • More information on Powdery mildew
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  • bacterialblight1
  • bacterialblight2
  • bacterialblight3

Bacterial Blight
Pseudomonas syringae pv. syringae

  • Dark brown leaf spots with yellow halos, center of spot may crack and fall out
  • Leaves on the end of the branch turn completely brown to black
  • Flower buds are limp and black
  • Infected buds are black and will not open
  • Common with cool wet spring weather
  • More information on Bacterial Blight
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  • ascochytablight1
  • ascochytablight2

Ascochyta Blight
Ascochyta syringae

  • Current year's shoots and flower stalks are wilted, brown and often form shepherd's crook
  • The stem of infected shoots is tan, shrunken and peppered with gray to pale orange spore producing structures
  • Water soaked, olive colored blotches appear on leaves in late summer; coalesce until entire leaf is brown
  • Leaf blotches may grow together until entire leaf is brown
  • More information on Ascochyta Blight

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