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 > Prunus > Rough, bumpy patches on branches

Print Icon Email Icon Share Icon

Prunus > Trunk/Branches > Rough, bumpy patches on branches

1 of 2
  • Image: Scurfy scale 1

Scurfy scale
Chionaspis furfura

  • Infested twigs and branches show dieback in canopy
  • Adults are white and covered by a white cocoon-like armor, which gives the appearance of white bumps along the stem or branches
  • Crawlers or juvenile scales are light purple
  • Cocoon-like armor can be seen year round but crawlers can be seen in June
  • More information on scale insects
2 of 2
  • Image: Black knot 1
  • Image: Black knot 2
  • Image: Black knot 3

Black knot
Apiosporina morbosa

  • Lumpy olive to black elongate swellings along all sizes of twigs
    and branches
  • Gall formation may cause leaves to wilt or not leaf out showing branch dieback
  • Rough black cracked swelling can occur on the main trunk
  • Most common on choke and pin cherry
  • More information on Black knot

Don't see what you're looking for?