This image shows severe yellowing of needles on the interior of a Blue Spruce. The yellowing of the needles is a sign that the roots of the tree are heavily impacted by one of several possible issues that are affecting the tree’s ability to grow healthy roots. In this case, a portion of the tree’s root zone was heavily trafficked by a nearby walkway that was recently replaced with some steps. Below the tree is a very moist and swampy area prone to flooding.
Although Blue Spruces tolerate a wide range of soil types and brief periods of flooding, they should not be planted in an area prone to persistent moisture. Excess water in soils prevent plant roots from getting enough oxygen and can promote the formation of destructive fungi. Compaction will reduce the amount of space between soil grains reducing oxygen availability and making water penetration difficult.
This tree is a prime example of the importance of site location when choosing landscape plantings. Unfortunately these issues are often noted well after serious damage to the plant has already occurred. Consulting your local arborist prior to selecting an appropriate site for a particular species can help you avoid wasting time and money.