Jean from Columbus, Ohio writes
The needles on the lower branches of our three Colorado spruce trees began turning brown. The disease is moving up the tree. We pruned the branches that had no green needles left and sprayed with Infuse two days ago (September 21st). I am wondering if I will notice improvement in the needles on the remaining affected branches
It sounds like you may be dealing with needlecast, a very common disease of blue spruce trees. This article has details about this disease's development, plus management tips. You will need to prune the infested branches and also potentially prune nearby trees to reduce the spread of the disease. How quickly a plant recovers from infection depends on many factors, ultimately, such as overall health of the plant, environmental conditions, and how early you are able to detect and treat the plant. While the Bonide INFUSE Systemic Disease Control is labeled for some conifer diseases, it will not treat needlecast. Garden Tech Daconil is labeled for needlecast on spruce trees, but keep in mind that this active ingredient can cause bleaching on blue spruce. We always recommend consulting with an arborist in your area if you are not sure what is afflicting your trees or if you need a more detailed assessment.
Answer last updated on: 09/25/2019