Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension
www.extension.umn.edu
612-624-1222

Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Birch > Unusual growth on trunk

Print Icon Email Icon Share Icon

Birch > Trunk/Branches > Unusual growth on trunk

1 of 2
  • Image: Canker rot 1
  • Image: Canker rot 2
  • Image: Canker rot 3

Canker rot
(aka. sterile conk or cinder conk)
Inonotus obliquus

  • Rough, cracked black, knob or cone like fungal growths protrudes from trunk, often near an old wound or branch stub
  • Internally fungal growth is spongy, colored yellow-brown to
    rust-brown
  • Infected trees often break at the point of the fungal growth
  • Mottled white and reddish brown wood decay can be seen within infected trunks
  • More information on Canker rot...
2 of 2
  • Image: Perennial nectria canker 1
  • Image: Perennial nectria canker 2
  • Image: Perennial nectria canker 3

Perennial nectria canker
Neonectria galligena

  • Sunken target shaped cankers on main trunk or branches
  • Cankers do not have bark and raised ridges of wood occur in target-like rings within the canker
  • Red to reddish orange raised cushion like bumps can occasionally be seen on the edge of the canker
  • Dead branches and twigs killed by girdling cankers
  • More information on Perennial nectria canker...

Don't see what you're looking for?

  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy