Rhizosphaera Needle Cast

Typical symptoms with inner spruce needles turning purplish in color.

Description: Fungal disease of spruce trees causing dieback, thinning and needle loss starting on the lower and inner crown.

Trees Affected: Spruce, Colorado blue spruce is most susceptible

What to look for: Needles turning purplish to brown on older needles, primarily in the lower and inside portion of the spruce and progressing outward and upward.

Treatment Options: Minimize the planting of Colorado spruce (which is very susceptible). Avoid planting a monoculture of spruce trees.  Instead plant a variety of pine, fir, larch and other evergreens mixed in with spruce trees.  Fungicide sprays can help for some cases, but treatment can be costly and time consuming.