Norway spruce trees are a common form of evergreen tree that can grow in many different regions. However, if they're transplanted, planted in inadequate conditions or don't receive proper care, their health can become compromised. Dying Norway spruces may lose foliage and have yellow needles, but they can usually be saved.
Diagnose the problem. Norway spruce trees can be damaged by lack of water, lack of nutrition, pests like spider mites and beetles, and over-fertilization. If you can pin down a specific reason for the tree's decline, treat that reason directly. If you can't, give the tree an all-around treatment.
Water the tree generously and keep the surrounding soil moist. Pay particular attention during dry spells, when the moisture in the soil can quickly evaporate. Lack of water is the number one killer of Norway spruce trees.
Make sure your Norway spruce is getting plenty of sun. If there are other trees blocking out the light, consider moving the spruce to another location, or pruning the other trees to allow sunlight to come through to the tree.
Sprinkle 1 tablespoon of 12-12-12 fertilizer onto the ground around the base of the tree to feed it. If the Norway spruce has yellowed needles, it's due to lack of sunlight and poor nutrition.
Spray your tree with an organic insecticide to eliminate mites and beetles.
Release lacewing moths and ladybugs. These natural predators will help eliminate the insects that might be feeding on your Norway spruce and killing it.