Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension
www.extension.umn.edu
612-624-1222

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

Print Icon Email Icon Share Icon

Marigold > Flowers > Discolored or spotted flowers

1 of 4
  • 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
2 of 4
  • 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
3 of 4
  • Cold damage 1
  • Cold damage 2
  • Cold damage 3

Cold Damage

4 of 4
  • 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

Don't see what you're looking for?

  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy