WSU Extension


True Fir
Annosus root rot 
Armillaria root rot 
Current-season needle necrosis 
Grovesiella canker 
Interior needle blight 
Needle casts 
Phytophthora root rot 
Rust (Pucciniastrum) 
Rust (Uredinopsis) 
Balsam twig aphid 
Balsam woolly adelgid 
Giant conifer aphids 
Spruce budworm 
Spruce spider mite 

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Caption: Fir needle cast
Photo by: R.S. Byther
True Fir : Needle casts
(revision date: 4/23/2014)

Needle casts on true fir are caused by several fungi. Infected trees develop brown or straw-colored needles which drop prematurely. Severely infected trees may have only current-season and one-year-old needles. The undersides of two-year-old and older needles develop elongate, dark brown to black fungal structures on either side of the midvein. The upper surface may display a single or double brown line of small dots in the midvein groove OR two distinct greenish or brown rows or wrinkles on either side of the midvein (not in the groove).
Management Options

Non-Chemical Management
  • Space plantings to provide good air circulation.
  • Control weeds in and around planting. Thin canopy and remove lower branches to reduce humidity.
Select non-chemical management options as your first choice!

Chemical Management

None recommended


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Caption: Fir needle cast
Photo by: R.S. Byther
Caption: Fir needle cast
Photo by: R.S. Byther