Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension

Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Willow > Scattered dead branches in canopy

Print Icon Email Icon Share Icon

Willow > Trunk/Branches > Scattered dead branches in canopy

1 of 3
  • Valsa canker 1
  • Valsa canker 2
  • Valsa canker 3

Valsa canker
Valsa sordida

  • Leaves on random branches wilt, turn yellow then brown
  • Random dead branches seen throughout the canopy
  • Sunken irregulary-elongated cankers with cracked bark at the edges occur on branches or the main trunk
  • On thick barked trees, cankers may not be visible
  • In wet weather curled tendrils of orange spores emerge from pimple-like fungal structures within infected branches
  • Common on trees stressed by drought, winter injury, wounds, insect feeding or other factors
  • More information on canker
2 of 3
  • Sapwood rot 1
  • Sapwood rot 2
  • Sapwood rot 3

Sapwood rot
Schizophyllum commune, Cerenna unicolor, Trametes versicolor

  • Dead branches within the canopy
  • Yellowing to brown leaves may be present
  • Groups or rows of small (
  • Schizophyllum shelf fungi are white and appear fuzzy on top
  • Cerrena fungi are white to greenish grey and have concentric rings on the surface
  • Trametes shelf fungi are tan to brown with darker rings
  • Wood below fungal shelves is yellowish to white, spongy, crumbly and decayed
  • Bark around fungal shelves is killed and often falls off
  • Common on trees stressed by drought, winter injury, wounds, mechanical injury or other factors
  • More information on Heart rot
3 of 3
  • 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

Don't see what you're looking for?