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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Ash > Growths on branches

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Ash > Trunk > Growths on branches

1 of 2
  • Image: Ash flower galls 1
  • Image: Ash flower galls 2
  • Image: Ash flower galls 3

Ash flower galls

  • Galls first form in April or May and remain on trees during summer and through winter
  • Galls are broccoli-like and green during summer and dark brown or black during winter
  • The galls are distorted clumps of male flowers
  • Produced by tiny eriophyid mites
  • More information on Ash flower galls
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  • Image: Oystershell Scale 1
  • Image: Oystershell Scale 2
  • Image: Oystershell Scale 3

Oystershell scales

  • Damage occurs during summer
  • Feeding causes foliage to yellow
  • Twig and branch dieback can occur when branches are heavily infested
  • Light to dark brown, elongate, 1/10 to 1/8 inch long, found feeding on branches
  • Heavy infestations can completely cover bark
  • More information on Oystershell scale

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