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 > Butternut > Dots, spots or blotches on leaves

Print Icon Email Icon Share Icon

Butternut > Leaves > Dots, spots or blotches on leaves

1 of 4
  • Image: Anthracnose 1
  • Image: Anthracnose 2
  • Image: Anthracnose 3

Anthracnose
Gnomonia leptosyla

  • Leaflets have circular brown spots surrounded by yellow tissue
  • Infected leaves turn yellow, then brown on the margins, curl and eventually fall off
  • Dark brown to black spots form on nut husks
  • Nuts drop prematurely
  • More information on Walnut Anthracnose...
2 of 4
  • Image: Leaf spot 1
  • Image: Leaf spot 2
  • Image: Leaf spot 3

Leaf spot
Mycosphaerella juglandis

  • Small black spots scattered across leaf
  • Dark brown veins and leaf tips are common due to many spots forming on leaf veins and leaf tips
  • As the disease progresses, leaves yellow and fall off
  • In mid-summer leaves appear yellow from a distance
  • Occurs on black walnut and butternut
  • More information on Leaf spot...
3 of 4
  • Image: Walnut lacebug 1
  • Image: Walnut lacebug 2
  • Image: Walnut lacebug 3

Walnut lacebug
Corythucha juglandis

  • Feeds on undersides of leaves with needle-like mouthparts causing white or yellow speckled or pinprick discolorations on leaf surface
  • Black dots or specks (droppings) are on the underside of leaves
  • Heavy feeding can cause severe discoloration and leaf drop
  • Lace bugs are 1/8 to 1/4 inch long; light colored bodies; intricate, lacy wings
  • Damage is most noticeable in mid to late summer
  • More information on Walnut lace bug...
4 of 4
  • Image: Downy leaf spot 1
  • Image: Downy leaf spot 2

Downy leaf spot
Microstroma juglandis

  • Leaf spots start as small round spots, but often grow together into large angular patches
  • Spots are pale yellow on upper leaf surface and powdery white below
  • As season progresses, spots can turn dry and brown
  • Occurs on black walnut, butternut and hickory
  • More information on Downy leaf spot...

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