WSU Extension

Hortsense

Spruce
 
Disease
Oil discoloration of foliage 
Rhizosphaera needle cast 
Rust 
Insect
Coneworms 
Cooley spruce gall adelgid 
Douglas fir tussock moth 
Pine needle scale 
Spruce aphid 
Spruce bud scale 
Spruce budworm 
Spruce needleminer 
Spruce spider mite 
White pine weevil 



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Caption: Spruce rust
Photo by: R.S. Byther
  
Spruce : Rust
(revision date: 4/23/2014)


Biology
Spruce rusts are fungal diseases that sometimes require an alternate host to complete their life cycle. There are many rust diseases of spruce, each with different alternate hosts. One spruce rust causes witches' brooms, or abnormally bushy growth of the branches. These witches' brooms gradually lose their healthy green color and turn yellowish or brownish as the fungus matures. Kinnikinnick is the alternate host.
Management Options


Non-Chemical Management
  • Remove alternate hosts (when known) from around spruce plantings.
  • Prune and destroy witches' brooms where possible.
Select non-chemical management options as your first choice!

Chemical Management

None recommended

Images

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Caption: Spruce rust
Photo by: R.S. Byther
Caption: Spruce rust: witches' broom
Photo by: R.S. Byther