Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Cotoneaster > Dead branches or branch dieback
Cotoneaster > Stems/branches > Dead branches or branch dieback
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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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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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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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Oystershell scale
Lepidosaphes ulmi
- Light to moderate infestations show little or no symptoms
- Severe infestations can cause chlorotic, stunted foliage
- Dieback and cracked bark can result from heavy infestations
- Light to dark brown, elongated, 1/10 to 1/8 inch long oyster-shell shaped scales found on bark
- More information on Oystershell Scale
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Quince Rust
Gymnosporangium clavipes
- Fruit becomes covered with orange tube-like spore producing structures
- Powdery orange colored spores are released in midsummer to fall
- Spindle-shaped swellings occur on petioles and green twigs
- Cankers may form on stems and cause dieback
- Occasionally yellow to orange leaf spots form
- More information on Quince Rust
