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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Hydrangea > Spots or blotches on leaves

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Hydrangea > Leaves > Spots or blotches on leaves

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Four-lined plant bug
Poecilocapsus lineatus

  • Small, round depressed spots which may be brown, black or translucent on leaves
  • Dead plant tissue may fall out causing a "shot hole" effect
  • Newly hatched nymphs are red with black wing pads and become yellowish green with a black stripe on each wing pad as they develop
  • Adults are one half inch long, yellowish to yellow green in color with four longitudinal black stripes on the wing covers
  • More information on four-lined plant bug
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Cercospera leaf spot
Cercospera aborescens

  • Leaf spots are first round and purple to brown
  • Older leaf spots have a thick purple border and a tan to gray enter
  • Severely infected leaves become yellow and may drop
  • Leaf spots often form on lower leaves first and gradually spread upward in the plant
  • More information on cercospera leaf spot
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Powdery mildew
Erisyphe polygoni

  • White spots or blotches on leaves
  • In severe cases leaves and young shoots may be completely covered with white powdery fungal growth
  • Leaves may be stunted, curled or puckered
  • Red or purple blotches may occur on upper leaf surfaces
  • More information on powdery mildew
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Anthracnose
Colletotrichum gleosporoides

  • Slightly sunken brown spots on leaves
  • As spots grow, dark brown rings give the spot a 'bull's eye' appearance
  • Spots can grow to 1 inch in diameter
  • Spots can be found on both leaves and flower petals
  • More information on anthracnose
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Botrytis Blight
Botrytis cinerea

  • Flower buds, petals, or entire blossoms turn tan to gray
  • Flowers become covered with fuzzy gray colored fungal spores in wet weather
  • Brown, round to irregular spots on leaves, often where petals have fallen
  • Common during cool wet weather
  • More information on Botrytis Blight

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