Extension Logo
Extension Logo
University of Minnesota Extension

Cedar-apple rust and related rust diseases

Quick facts

  • Cedar-apple rust and three related rust fungi need plants from two plant families to complete their life cycle; Cupressaceae family (eastern red cedar and other junipers) and Rosaceae (apple, hawthorn, serviceberry).
  • Bright orange to red leaf spots occur on trees and shrubs in the Rosaceae family (apple, hawthorn, serviceberry, etc.).
  • Hardy woody galls, witches brooms and swollen stems covered in gummy orange fungal growth in spring occur on juniper and eastern red cedar.
  • Cedar-apple rust and related rust fungi rarely cause serious damage to their hosts and do not require management.
  • Do not plant eastern red cedar and juniper within a few hundred yards of plants from the Rosaceae family (apple, crabapple, hawthorn, serviceberry etc.)
  • Some disease resistant varieties are available.  

How to identify rust

These diseases require plants from two different families in order to complete their life cycle; one plant from the Cupressaceae family (red cedar, juniper) and the other from the Rosaceae family (crabapple, hawthorn, serviceberry). Symptoms are very different on each type of plant.


Managing rust


Rebecca Koetter and Michelle Grabowski, Extension educator

Reviewed in 2018

Share this page:

© 2019 Regents of the University of Minnesota. All rights reserved. The University of Minnesota is an equal opportunity educator and employer.