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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Ash > Leaves yellow and small

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Ash > Leaves > Leaves yellow and small

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  • Image: Environmental stress, tree top - no leaves
  • Image: Environmental stress, brown leaves
  • Image: Environmental stress, missing leaves

Environmental stress
Drought, compact soils, flood damage, winter injury, other

  • Dead branches in the canopy
  • Leaves wilt and turn brown at the tips and the margins first, then completely brown
  • Many weak young shoots/sprouts at the base of the tree
  • Leaves appear drooped or wilted within canopy
  • More information on caring for trees and shrubs
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  • Image: Stem girdling roots, trunk base 1
  • Image: Stem girdling roots, trunk base 2
  • Image:Stem girdling roots, tree

Stem girdling roots

  • A root circling the trunk of the tree may be seen at the soil line
  • The trunk may become sunken in or compressed where it contacts the root
  • If the girdling root is below ground the trunk will lack the natural widening or flare at the soil line, but rather will go straight into the earth like a telephone pole
  • Affected trees have slow growth, poor color, change color and lose their leaves early in the fall
  • Affected trees commonly exhibit water-stress symptoms such as marginal leaf scorch, wilting, sudden leaf fall.
  • Affected trees commonly exhibit excessive and abnormal winter damage including true frost cracks and dieback
  • More information on Stem girdling roots
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  • Image: Verticillium, dead leaf patches
  • Image: Verticillium, dead tree crown
  • Image: Verticillium, twig up close

Verticillium
Verticillium dahliae

  • Leaves are small and yellowed in chronic infections
  • Leaves turn brown from the edges and tips, wilt and die in severe infections
  • Leaf symptoms are often seen on only one branch in the canopy
  • Tan to pale brown streaks often can be seen in the sapwood if the bark is peeled back, appearing as rings or arcs in a cross cut
  • Symptoms may develop over a single growing season, or over several years
  • More information on Verticillium wilt
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  • Image: Oystershell scales, defoliation
  • Image: Oystershell scales, twig up close
  • Image: Oystershell scales, twig with scales

Oystershell scales

  • Damage occurs during summer
  • Feeding causes foliage to yellow
  • Twig and branch dieback can occur when branches are heavily infested
  • Light to dark brown, elongate, 1/10 to 1/8 inch long, found feeding on branches
  • Heavy infestations can completely cover bark
  • More information on Oystershell scale
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  • Image: Ash yellows, missing leaves in crown
  • Image: Ash yellows, yellow leaves
  • Image: Ash yellows, leaves up close

Ash yellows phytoplasma

  • Infected plants grow very slowly, and have a sparse thin canopy of leaves
  • Leaves are small, yellow, often folded or cupped and grow in clumps along the branch
  • Branches die throughout the canopy
  • Many weak young sprouts with small yellow leaves arise from the base of the tree
  • More information on ash yellows

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