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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Hickory > Tree breaks or falls over

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Hickory > Whole tree > Tree breaks or falls over

1 of 4
  • Armillaria root rot 1
  • Armillaria root rot 2
  • Armillaria root 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
2 of 4
  • Flathead appletree borer 1
  • Flathead appletree borer 2
  • Flathead appletree borer 3

Flathead appletree borer
Chrysobothris femorata

  • White froth usually oozes from cracks in bark
  • Dead branches in crown of older trees
  • Bark becomes sunken at site of injury; bark may crack later
  • Injured areas become larger and deform with annual attacks
  • Young and stressed trees are most at risk
  • Larvae are cream-colored, flattened bodies, about 1 inch long
  • Long tunnels under the bark girdle trees and cause structural weakness
  • More information on Flathead appletree borer
3 of 4
  • Heart rot 1
  • Heart rot 2
  • Heart rot 3

Heart rot
Fomes fomentarius

  • Canopy may show no symptoms, or may have small, yellowing leaves or dead branches depending on the extent of decay
  • In cross section, the wood at the center of the trunk is white, mottled, soft and crumbly
  • Hoof-shaped, silvery-grey to brown, fungal fruiting bodies up to 8 inches across arise along the stem; often near a pruning wound, crack or other wound
  • More information on Heart rot
4 of 4
  • Ganoderma root and butt rot 1
  • Ganoderma root and butt rot 2
  • Ganoderma root and butt rot 3

Ganoderma root and butt rot
Ganoderma spp.

  • Leaves are small and may yellow and drop
  • Canopy appears thin with few leaves and multiple dead branches
  • Fungal conks, 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 the 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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