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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Annuals and Perennials > Marigold > Discolored or spotted flowers

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Marigold > Flowers > Discolored or spotted flowers

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  • Powdery mildew 1
  • Powdery mildew 2
  • Powdery mildew 3

Powdery Mildew
Golovinomyces (syn. Erysiphe) cichoracearum

  • Powdery, fluffy white spots and blotches on leaves, stems, and flower parts
  • Tiny black round spheres may be visible within white spots late in the season
  • Spots typically start on lower leaves but can spread to cover the entire plant
  • Severely infected leaves may be completely covered in white or grayish white fungi
  • In some cases, leaves become curled or twisted or turn yellow due to the infection
  • More information on powdery mildew
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  • Gray mold 1
  • Gray mold 2
  • Gray mold 3

Gray Mold
Botrytis cinerea

  • Irregular brown spots on leaves
  • Brown blossoms or petals; flowers drop off prematurely
  • Gray fuzzy mold develops on rotted tissue under humid conditions
  • Disease develops during cool, wet weather
  • More information on gray mold
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  • Cold damage 1
  • Cold damage 2
  • Cold damage 3

Cold Damage

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  • Leaf spots on flower 1
  • Leaf spots 2
  • Leaf spots 3

Leaf Spots
Alternaria sp., Septoria tageticola

  • Spots on leaves, stems, and flowers
  • Spots vary in size and color, may be irregular to oval in shape, and may or may not have purple margins
  • Centers of leaf spots may be speckled with tiny black dots
  • Disease starts on lower leaves and progresses upward
  • African marigold varieties are the most susceptible to leaf spots
  • More information on leaf spots

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