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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Lilac > Leaves discolored yellow

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Lilac > Leaves > Leaves discolored yellow

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  • witchesbroom1
  • witchesbroom2
  • witchesbroom3

Witches' Broom
Candidatus Phytoplasma fraxini

  • Dense clusters of short, thin twigs originate from one area of stem
  • Leaves may be small, distorted and yellow
  • Brooms are common at the ends of branches and clustered at the very base of the plant
  • Entire canopy is pale green to yellow, some leaves with brown margins
  • Branches may die and shrub will decline
  • More information on Witches' Broom
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  • oystershell1
  • oystershell2
  • oystershell3

Oystershell scale
Lepidosaphes ulmi

  • Light infestations do not exhibit obvious symptoms
  • Severe infestations can cause chlorotic, stunted foliage
  • Dieback and cracked bark can result from heavy infestations
  • Light to dark brown, elongated, 1/10 to 1/8 inch long oyster-shell shaped scales found on bark.
  • More information on Oystershell Scale
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  • verticilliumwilt1
  • verticilliumwilt2

Verticillium wilt
Verticillium dahlia

  • Leaves on one to several branches turn red to yellow, wilt, die and fall off
  • Dark olive to gray streaks are often visible in the sapwood if the bark is peeled back
  • The entire canopy may show symptoms in a single season or take several years
  • Symptoms are often most obvious in late summer and autumn but can occur throughout the growing season
  • More information on Verticillium wilt

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