Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Ash > Dots, spots, blotches or rings on leaves
Ash > Leaves > Dots, spots, blotches or rings on leaves
1 of 5
Ash plant bugs
- Damage occurs during spring but will be present remainder of summer
- Feeding cause speckled, pinprick whitish or yellowish discoloration; does not cause leaf drop
- Severe feeding can result in brown, dead areas, especially along edges of leaflets
- Nymphs bright red, then turn yellowish or brownish
- Adults brown and yellow with heart-shaped mark
- More information on Ash plant bugs
2 of 5
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
3 of 5
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
4 of 5
Powdery Mildew
Phylactinia fraxini
- Powdery white coating on leaves, green stems, and buds
- Common on lower leaves and leaves that are shaded
- In severe infections leaves may curl or turn yellow (rare)
- More information on Powdery Mildew
5 of 5
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
