Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Ash > Distorted leaves
Ash > Leaves > Distorted leaves
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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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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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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
- More information on Cottony ash psyllids
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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
- More information on Viruses
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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
