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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Hawthorn > Discolored or cracked area of bark

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Hawthorn > Trunk/branches > Discolored or cracked area of bark

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  • Image: Fire Blight 1
  • Image: Fire Blight 2
  • Image: Fire Blight 3

Fireblight
Erwinia amylovora

  • Infected leaves wilt, turn gray then dark brown to black
  • Young shoots curl over into a shepherd’s crook
  • Infected blossoms first turn gray, then black
  • Infected leaves and mummified fruit remain attached to the tree, often into winter
  • Branch cankers have dark, sunken & cracked bark, sapwood is streaked reddish brown
  • Drops of sticky honey-colored liquid can be seen on infected plant parts in warm wet weather
  • More information on Fireblight...
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  • Image: Black Rot 1
  • Image: Black Rot 2

Roundheaded appletree borer
Saperda candida

  • Dead stems and stem breakage
  • Cracks or splits in bark on lower stems
  • Areas of darkened bark and sap oozing from entrance hole
  • Larvae tan to cream colored and grub-like, about 1 – 1 ½" long
  • Adult brown with two white stripes, about ¾" long with equally long antennae
  • More information on Roundheaded appletree borer...

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