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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Ash > Distorted leaves

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Ash > Leaves > Distorted leaves

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  • Image: Ash leaf curl aphids, brown leaves
  • Image: Ash leaf curl aphids, curled leaves
  • Image: Ash leaf curl aphids, insects up close

Ash leaf curl aphids

  • Damage first occurs May and June and is present the remainder of season
  • Ash leaves become curled and distorted
  • Often covered with honeydew (sticky substance) and white waxy material
  • Small, 1/8 inch long, whitish woolly aphids are inside leaves
  • More information on Ash leaf curl aphids...
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  • Image: Antracnose, leaves up close 1
  • Image: Antracnose,leaves up close 2
  • Image: Antracnose, leaves on tree

Anthracnose
Discula fraxinea

  • Tan to brown irregular spots on leaves, often causing leaves to be curled or deformed
  • In severe infection leaves may wilt and fall off, part or all of the tree may lose its leaves
  • Common on young leaves in cool wet spring weather
  • Lower leaves and leaves in the inner canopy are often infected first, or most severely
  • More information on Anthracnose...
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  • Image: Cottony ash psyllids, leaves up close 1
  • Image: Cottony ash psyllids, leaves up close 2
  • Image: Cottony ash psyllids, leaves up close 3

Cottony ash psyllids

  • Damage first occurs May and June and is present the remainder of season
  • Leaves fold over along edge of leaflets
  • Later in season, tips of leaflets can blacken, while leaves shrivel up
  • Psyllids are small, 1/16 - 1/8; nymphs exude white, waxy material inside leaflets
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  • Image: Virus, leaves up close 1
  • Image: Virus, leaves up close 2
  • Image: Virus, leaves up close 3

Virus
White Ash Mosaic Virus and many others

  • Random pattern of yellow and shades of green on leaves
  • Blocky white or yellow irregular spots or rings on leaves
  • Leaves may be distorted or unusually shaped
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  • Image: Rust, wart-like spot 1
  • Image: Rust, wart-like spot 2
  • Image: Rust, wart-like spot 3

Rust
Puccinia sparganioides

  • Yellow to bright orange wart like spots on leaves and green stems
  • Clusters of tiny cup like structures grow out of spots and release powdery orange spores
  • Leaves and stems may be bent or twisted where infected
  • In severe cases leaves may turn brown and fall off (very rare in MN)
  • More information on Rust...

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