Evergreen tree replacement - Ask Extension
I have mature spruce trees planted in my yard at 20' spacing, staggered in double rows along 400' for a privacy screen. Quite a few of them are showin...
Knowledgebase
Evergreen tree replacement #947646
Asked October 25, 2026, 12:42 PM EDT
I have mature spruce trees planted in my yard at 20' spacing, staggered in double rows along 400' for a privacy screen. Quite a few of them are showing dead or dying lower branches. Should these branches be trimmed off the tree, including any branches with only green growth on the very tips? What would be the best management practice for these trees? What would be an alternative evergreen tree option to plant between these existing trees to establish a new privacy screen?
Olmsted County Minnesota
Expert Response
Thank you for writing.
That looks like needle cast. There are two varieties.
Essentially all spruce in MN are dying of heat stress.
https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/rhizosphaera-needle-cast
Less likely is cytospora culture. https://extension.umn.edu/garden-and-home/yard-and-garden/gardening-in-minnesota/yard-and-garden-problems/cytospora-canker
Given that you have so many trees and such a costly problem, I suggest that you call an arborist. See my signature line.
That looks like needle cast. There are two varieties.
Essentially all spruce in MN are dying of heat stress.
https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/rhizosphaera-needle-cast
Less likely is cytospora culture. https://extension.umn.edu/garden-and-home/yard-and-garden/gardening-in-minnesota/yard-and-garden-problems/cytospora-canker
Given that you have so many trees and such a costly problem, I suggest that you call an arborist. See my signature line.
