Needles Yellowing and Dropping on Evergreens
Don't worry if your evergreen has yellow or brown needles all along the trunk. This is a common occurrence called seasonal needle drop.
Evergreens shed some of their older needles every year. They lose a larger number of needles in the late summer or fall following a summer drought or other environmental stress. Some species like white pine lose their needles after two years making the plants look unhealthy and their owners quite worried. While Spruce tend to hold their needles longer, masking those lost to seasonal needle drop.
Proper watering and care will prepare your plants for winter and keep them healthy for seasons to come.
Diseased evergreens will have yellow and brown needles on the whole branch, scattered branches, or isolated portions of the trees. Not just along the trunk.
If you suspect a disease problem, contact a certified arborist. They can diagnose the problem and recommend treatment if needed.
A bit more information: Find a certified arborist in your area by visiting the International Society of Arboriculture website www.isa-arbor.com or Trees are Good www.treesaregood.com. Certification is voluntary and certified arborists (tree care professionals) are individuals with experience and education that have passed an exam covering information on a wide range of tree care practices.