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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Annuals and Perennials > Impatiens > Discolored leaves

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Impatiens > Leaves > Discolored leaves

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  • Two-spotted spider mite damage 1
  • Two-spotted spider mites 2
  • Two-spotted spider mites 3

Two-spotted Spider Mite
Tetranychus urticae

  • Active during summer, particularly abundant during hot, dry weather
  • Pale spots or 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 Two-Spotted Spider Mites (86 K PDF)
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  • Downy mildew 1
  • Downey mildew 2
  • Downy mildew 3

Downy Mildew
Plasmopara obducens

  • Leaves turn pale green to yellow and may curl slightly downward downy  white to fungal growth on underside of leaves
  • Plants become yellow in color and stunted
  • Infected leaves prematurely drop from the plant leaving a barren stalk with few leaves
  • Disease favors cool, wet weather
  • More information on Downy Mildew
3 of 5
  • Gray mold 1
  • Gray mold 2
  • Gray mold 3

Gray Mold
Botrytis cinerea

  • Brown spots on leaves with concentric brown rings like a bull’s eye
  • 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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  • Root rot plant 1
  • Root rot close up 2
  • Root rot plant 3

Root Rot
Pythium spp., Rhizoctonia solani

  • Leaves turn yellow and wilt
  • Plants are stunted
  • With Rhizoctonia sp., the base of the stem may turn brown and crack
  • Roots have brown sunken areas and lack root hairs
  • The outer root tissue is 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
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  • Sunscald 1
  • Sunscald 2
  • Sunscald 3

Sunscald

  • Exposed parts of leaves bleach yellow to white
  • In severe cases, affected areas turn brown and brittle
  • Symptoms more severe in dry hot weather
  • More information on Sunscald

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