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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Oak > Leaf edges brown, center of leaf green

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Oak > Leaves > Leaf edges brown, center of leaf green

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  • Image: Oak wilt 1
  • Image: Oak wilt 2
  • Image: Oak wilt 3

Oak wilt
Ceratocystis fagacearum

  • Leaves wilt, leaf edges and tips turn brown, with a green center
  • In red oak group symptoms are first seen in the top of the canopy, disease progresses to the entire canopy and kills tree in 1 to 3 months
  • Infected trees drop their leaves
  • In white oak group symptoms appear in one branch, disease progresses slowly from 1 to 5 years before death
  • In white oak group - Peel back layer of bark on symptomatic branch to reveal brown streaking on wood
  • Symptoms appear in whole groups of trees as infection spreads through root graft
  • More information on Oak wilt...
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Bur oak blight
Tubakia iowensis

  • Infects only bur oaks - small acorn variety
  • Spring and early summer, leaf veins on lower leaf surface have dark brown dots or short lines
  • Mid-summer and fall, random lengths of leaf vein turn brown; some expand into brown wedge shaped areas on leaves
  • Leaves may turn completely brown, some drop early
  • Small raised black dots form on the petiole (stem) of infected leaves
  • Some leaves remain attached through winter
  • Symptoms appear in lower, inner canopy first. Disease progresses upward and outward over multiple seasons
  • More information on Bur oak blight...
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  • Image: Oak anthracnose 1
  • Image: Oak anthracnose 2
  • Image: Oak anthracnose 3

Oak anthracnose
Discula quercina

  • Leaves have scattered brown, irregular spots that can coalesce into nearly completely brown leaves
  • Affected leaves become wrinkled, cupped or curled especially around leaf edges
  • On severely infected trees, leaves fall off early in the season, trees soon sends out new leaves
  • Damage is most common on lower and interior branches
  • Damage most common in spring as leaves are growing during wet weather
  • Most affected are trees within white oak group (white oak, bur oak, swamp white oak)
  • More information on Oak anthracnose...
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  • Image: Stem girdling roots 1
  • Image: Stem girdling roots 2
  • Image: Stem girdling roots 3

Stem girdling roots

  • Affected trees commonly exhibit water-stress symptoms such as marginal leaf scorch, wilting, sudden leaf fall
  • Leaves stunted, exhibit poor summer color, change color and drop early in fall
  • Affected trees commonly exhibit excessive and abnormal winter damage including frost cracks and dieback
  • A root circling the trunk of the tree may be seen at the soil line
  • Trunk may be sunken in or compressed where it contacts the root
  • If girdling root is below ground, the trunk will lack the natural widening or flare at the soil line so will go straight into the earth like a telephone pole; trees often exhibit an abnormal lean
  • More information on Stem girdling roots...
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  • Image: Drought 1
  • Image: Drought 2
  • Image: Drought 3

Drought

  • Leaf margins and branch extremities usually brown and wilt first
  • Leaves often yellow (chlorotic)
  • Uniform wilting or browning of leaves throughout the tree
  • Severe drought stress may cause dieback of individual branches
  • Drought-stressed trees and shrubs often drop their leaves abnormally early
  • More information on Drought...
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  • Image: Deicing salt injury 1
  • Image: Deicing salt injury 2

Deicing salt injury

  • Soil salt damage causes leaf edges or margins to appear burnt or scorched progressing toward the mid-vein
  • Soil salt damage can mimic nutrient deficiencies, e.g., yellowing foliage on deciduous plants
  • Salt spray causes branches to become tuft-like (a.k.a. witches’ broom)
  • Run-off salt kills roots which results in die-back of most branches
  • Affected trees leaf out later than other non-infected trees
  • All deicing damage most noticeable in spring
  • More information on Deicing salt injury...
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  • Image: Bacterial leaf scorch 1
  • Image: Bacterial leaf scorch 2
  • Image: Bacterial leaf scorch 3

Bacterial leaf scorch
Xylella fastidiosa

  • Leaf edges and tips turn brown, with a green center, leaves appear scorched
  • Symptoms often appear on one to a few branches, the entire canopy slowly becomes affected over several years
  • Often only one tree within a cluster is affected
  • Symptoms often appear in August or September
  • Common on trees within the red oak group (red oak, northern pin oak)
  • More information on Bacterial leaf scorch...

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