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 > Osteospermum > Discolored leaves

Print Icon Email Icon Share Icon

Osteospermum > Leaves > Discolored leaves

1 of 6
  • Root rot 1
  • Root rot 2
  • Root rot 3

Root Rot
Rhizoctonia solani and Pythium spp.

  • Leaves turn yellow and wilt
  • Plants are stunted
  • The base of the stem may turn brown and crack
  • Roots have brown sunken areas and lack root hairs
  • The outer root tissue may be easily removed leaving behind thin, stringy root cores.
  • Disease favors cool, wet soil with poor drainage
  • Lab test necessary to distinguish between Rhizoctonia and Pythium Root Rot
  • More information on Rhizoctonia root rot
  • More information on Pythium root rot
2 of 6
  • Spider mites 1
  • Spider mites 2
  • Spider mites 3

Spider Mites
Tetranychus urticae

  • Active during summer, particularly abundant during hot, dry weather
  • Pale stippling appears on the upper leaf surface
  • Leaves are discolored off green to whitish, yellowish, or bronze
  • Premature leaf drop can occur
  • Visible webbing occurs on infected leaves when populations are high
  • Adults are tiny (1/50th inch long) and oval, greenish or yellowish with a dark spot on either side of the body
  • More information on spider mites
3 of 6
  • Aster yellows 1
  • Aster yellows 2
  • Aster yellows 3

Aster Yellows
Phytoplasma

  • Part or all of the leaves may turn yellow
  • Flowers fail to develop, remain small green and may be distorted
  • Clumps of weak shoots known as witches broom develop throughout the plant or on flower stalks
  • More information on aster yellows
4 of 6
  • White mold 1
  • White mold 2
  • White mold 3

White Mold
Sclerotinia sclerotiorum

  • Entire plant or single branch wilts, leaves turn brown and die
  • Wilted stems are discolored, tan to off-white
  • Fluffy, white cotton-like fungal growth may been seen on infected plants when humidity is high
  • Black hard spheres ranging in size from 1/16 to 1/2 inch can be found clinging to the outside an infected stem or embedded inside the dead stem
  • Entire plant or single branch wilts, leaves turn brown and die
  • More information on white mold
5 of 6
  • 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
6 of 6
  • Cold damage 1
  • Cold damage 2

Cold Damage

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