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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Basswood/Linden > Dead branches in canopy

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Basswood/Linden > Trunk/Branches > Dead branches in canopy

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  • Image: Verticillium wilt 1
  • Image: Verticillium wilt 2
  • Image: Verticillium wilt 3

Verticillium wilt
Verticillium dahliae

  • Leaves turn brown from the edges and tips, wilt and die in severe infections
  • Leaves are small and yellowed in chronic infections
  • Leaf symptoms are often seen on only one or a few random branches in the canopy
  • 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: Deicing salt injury 1
  • Image: Deicing salt injury 2
  • Image: Deicing salt injury 3
  • - CLICK PHOTO TO ENLARGE -

Deicing salt injury

  • Run-off salt kills roots which results in die-back of most branches
  • Soil salt damage causes leaf edges or margins to appear burnt or scorched progressing toward the mid-vein
  • Affected trees leaf out later than other non-infected trees
  • Damage most noticeable in spring
  • More information on Deicing salts...
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  • Image: Branch cankers 1
  • Image: Branch cankers 2
  • Image: Branch cankers 3

Branch cankers
Botryosphaeria obtusa and other fungi

  • Random dead branches seen throughout canopy
  • Leaves on random branches wilt, turn yellow then brown during the growing season
  • Infected branches don’t leaf out in spring
  • Cankers are brown to black sunken areas on branch that may have cracked bark and discolored sapwood
  • Common on trees stressed by drought, winter injury, wounds, insect feeding or other factors
  • More information on Branch cankers...
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  • Image: Linden borer 1
  • - CLICK PHOTO TO ENLARGE -

Linden borer
Saperda vestita

  • Lower branches, lower trunk and surface roots are attacked resulting in limbs in canopy dying; eventually the entire tree is killed after high infestation
  • Thinning of the canopy
  • Round exit holes ¼ inch wide in trunk
  • Adults up to ¾ to 7/8 inch long, longhorns, black body covered by dense olive-yellow hairs; larvae are legless, cylindrical and 7/8 to 1 inch long
  • Littleleaf lindens are preferred hosts
  • More information on Linden borer...
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  • Image: Ganoderma root and butt rot 1
  • Image: Ganoderma root and butt rot 2
  • Image: Ganoderma root and butt rot 3

Ganoderma root and butt rot
Ganoderma spp.

  • Canopy appears thin with few leaves and multiple dead branches
  • Leaves are smaller in size and turn yellow earlier than normal
  • Fungal conks, a semicircle shelf fungi, can be found from the base of the tree up to 3 feet high on the trunk
  • Conks are reddish brown and shiny on top, white and porous underneath, a rim of white may be visible on the edge of growing conks
  • Infected wood at the base of the tree is white, soft, stringy or spongy
  • Infected trees frequently break or fall over in storms
  • More information on Ganoderma root and butt rot...
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  • Image: Perennial nectria canker 1
  • Image: Perennial nectria canker 2
  • Image: Perennial nectria canker 3

Perennial nectria canker
Neonectria galligena

  • Dead branches and twigs killed by girdling cankers
  • Sunken dark brown cankers on main trunk or branches
  • Cankers become crater like cavities with age
  • Red to reddish orange raised cushion like bumps can occasionally be seen on the edge of the canker
  • More information on Perennial nectria canker...
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  • Image: Sapwood rot 1
  • Image: Sapwood rot 2
  • Image: Sapwood rot 3

Sapwood rot
Schizophyllum commune and Cerrena unicolor

  • Dead branches within the canopy
  • Groups or rows of small (<2 inches wide) semi-circle self fungi along killed branches or on the main trunk
  • Schizophyllum shelf fungi are white and appear fuzzy on top
  • Cerrena shelf fungi are white to greenish grey and have concentric rings on the surface
  • Common on trees with an open wound or crack
  • Wood below fungal shelves is yellowish to white, crumbly and decayed; bark around fungal shelves is killed and often falls off
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  • Image: Drought stress 1
  • Image: Drought stress 2
  • Image: Drought stress 3

Drought stress

  • Dead branches in the canopy
  • Leaves wilt and turn brown at the tips and the margins first, then completely brown
  • Leaves appear drooped or wilted within canopy
  • The ground beneath the tree is littered with yellow to brown leaves
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  • Image: Stem girdling roots 1
  • Image: Stem girdling roots 2
  • Image: Stem girdling roots 3

Stem girdling roots

  • Affected trees are often stunted, exhibit poor summer 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
  • A root circling or running against one or more sides of 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 so will go straight into the earth like a telephone pole; trees often exhibit an abnormal lean
  • Many weak young shoots/sprouts at the base of the tree
  • Trees break off at the soil line during wind storms
  • More information on Stem girdling roots...

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