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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Cotoneaster > Bark on branches sunken, cracked or blistered

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Cotoneaster > Stems/branches > Bark on branches sunken, cracked or blistered

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  • Image: Winter Injury 1
  • Image: Winter Injury 2
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Fire blight
Erwinia amylovora

  • Infected flowers appear water-soaked, shrivel and turn brown or black
  • Leaves wilt, turn reddish brown; appear as though scorched by fire and cling to twigs
  • Infected shoots turn brown and bend into a shepherds' crook
  • Cankers on older branches cause bark to be dark, cracked and sunken
  • More information on fire blight
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  • Image: Black Rot 1
  • Image: Black Rot 2
  • Image: Black Rot 3

Botryosphaeria canker
Botryosphaeria dothidea

  • Leaves on one or more branches wilt, die and turn brown
  • Bark on affected branches is darker, cracked, or blistered at the site of the canker
  • Wood beneath the canker is dark brown
  • Common on shrubs stressed by drought, winter injury and other factors
  • More information on Botryosphaeria canker
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  • Image: Fire Blight 1
  • Image: Fire Blight 2
  • Image: Fire Blight 3

Nectria canker
Nectria cinnabarina

  • Dead branches and twigs, often first observed in early spring
  • Bark at the base of dead branches is slightly sunken, discolored or cracked
  • Tiny, pink, pale orange or cream colored cushion-like spore-producing bodies are visible in cracks in bark in spring
  • In summer, smaller coral colored bumps push through cracks
  • In autumn these spore-producing structures are dark brown or black
  • More information on Nectria canker

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