Needle cast in blue spruce
We just planted two 6 ft tall blue spruce. They look great right now, but we are worried about them getting this problem. What can we do to protect our trees to keep them from getting needle cast?
Washtenaw County Michigan
When people say needle cast, they are usually referring to Rhizosphaera Needle cast which is a fungal problem that affects blue spruce - the Colorado blue spruce in particular. While there are fungicide sprays that can be used to prevent the spread of the problem on a tree, it is not usually recommended to spray unless the problem has actually been diagnosed as present. Different problems can have similar symptoms. Good information on blue spruce and needle cast can be found at:
and also Penn State Extension: http://extension.psu.edu/pests/ipm/agriculture/christmas-tree/pest-fact-sheets/needle-discoloration-...