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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Annuals and Perennials > Aster > Spots on leaves

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Aster > Spots on leaves

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  • Rust 1
  • Rust 2
  • Rust 3

Coleosporium asterum and several species of Puccinia

  • Raised orange spots on the underside of leaves and along stems
  • Faint yellow spots on upper side of leaves
  • Powdery orange spores rub off of infected leaves and can be seen with a white tissue paper
  • Older infected leaves on lower part of the plant turn brown and dry up
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  • Powdery Mildew 1
  • Powdery Mildew 2
  • Powdery Mildew 3

Powdery Mildew
Erysiphe cichoracearum

  • Powdery, fluffy white spots and blothces 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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