Colorado Blue Spruce is usually a healthy, pest resistant landscape evergreen for eastern Nebraska. Unfortunately, even this seemingly healthy plant can be affected by disease and Rhizosphaera Needle READ MORE http://byf.unl.edu/web/byf/Rhizosphaera
Several conifer species can be infected by Rhizosphaera Needlecast, but this disease is most commonly found on Blue Spruce trees. Healthy Blue Spruce trees will retain their needles for 5 – 7 years. READ MORE https://www.natlarb.com/html/rhizosphaera_needlecast.html
Needles of Colorado blue spruce (Picea pungens) dropping due to rhizosphaera needlecast disease
Rhizosphaera needlecast is caused by the fungus, Rhizosphaera kalkhoffii. The disease causes death an READ MORE http://www.mobot.org/gardeninghelp/plantfinder/ipm.asp...
Norman Wolf, Retired San Juan County Extension Agent
Natalie Goldberg, Extension Plant Pathologist
Robert Cain, Forest Pest and Detection Specialist
College of Agriculture, Consumer and Environment READ MORE http://aces.nmsu.edu/pubs/_h/h-163.html
Ohio State University Extension Fact Sheet
Plant Pathology
2021 Coffey Road, Columbus, OH 43210-1087
Rhizosphaera Needlecast on Spruce
HYG-3059-96
Nancy J. Taylor
Stephen T. Nameth
Spruce, READ MORE http://ohioline.osu.edu/hyg-fact/3000/3059.html