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

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Catalpa > Leaves > Leaves discolored yellow to brown

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  • Image: Fire Blight 1
  • Image: Fire Blight 2
  • Image: Fire Blight 3

Verticillium wilt
Verticillium dahliae and V. albo-atrum

  • Leaves are small and yellowed in chronic infections
  • Leaves wilt, eventually turn brown and die in severe infections
  • Leaf symptoms are often seen on only one or a few random branches in the canopy
  • Dark olive to gray streaks are often visible in the sapwood if the bark is peeled back, appearing as rings or arcs in a cross section
  • Symptoms may develop over a single season, or over several years
  • More information on Verticillium wilt
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  • Image: Apple Maggot 1
  • Image: Apple Maggot 2
  • Image: Apple Maggot 3

Iron chlorosis

  • Leaves yellow with green veins
  • Most severe on branch tips or new growth
  • Affected trees have poor growth, undersized leaves
  • Symptoms occur on Catalpas in alkaline soils
  • More information on Iron chlorosis
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  • Image: Black Rot 1
  • Image: Black Rot 2
  • Image: Black Rot 3

Sapwood rot
Schizophyllum commune

  • Dead branches within the canopy
  • Yellowing to brown leaves may be present
  • Groups or rows of small (< 2 inches wide) semi-circle shelf fungi along killed branches or on the main trunk, often near cracks or wounds
  • Schizophyllum shelf fungi are white and appear fuzzy on top
  • Wood below fungal shelves is yellowish to white, spongy, crumbly and decayed
  • Bark around fungal shelves dies and often falls off
  • Common on trees stressed by drought, winter injury, wounds, mechanical injury or other factors
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  • Image: White Rot 1
  • Image: White Rot 2
  • Image: White Rot 3

Armillaria root rot
Armillaria spp.

  • Infected trees have poor growth, dead branches in the upper canopy, undersized and/or yellow leaves
  • Flat white sheets of fungal growth (mycelial fans) between the bark and sapwood at the base of infected trees
  • Thick black, shoestring-like fungus can sometimes be seen under the bark, around roots and in the soil around the base of the tree
  • Wood is decayed, white, soft and spongy; this may extend from the base of the tree well up into the trunk
  • Trees frequently break or fall over in storms
  • Clusters of honey-colored mushrooms may grow at the base of the tree in fall
  • More information on Armillaria root rot

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