Fall brings us beautiful colors on Oaks, Maples and other trees in New England, but fall also brings changes in the needles of conifers, such as Pines, Spruces and Arborvitae.
These types of trees are commonly termed evergreens because their needles stay green year round. Well, at least most of the needles stay green. The average lifespan of evergreen needles is three years. In the fall of their third year, the oldest needles turn yellow and drop from the tree, leaving only the one and two year old needles on the outside of the branch.
New needles form in the spring, at the tips of limbs, so again there is three years of needle growth on the tree. So if your evergreen has been healthy all season and then suddenly, in September or October, some of the needles turn yellow, don’t be alarmed, it’s natural - except in seasons of extended drought, where yellow needles can indicate tree health issues. Such is the case in years like this year where we have experienced a season with excessive drought stress. This will lead to more than the average amount of needle drop, and in some cases, defoliation.
If you are concerned about your evergreens, please request a free consultation with an Arborist, as they are trained to identify drought stress and differentiate it from natural third year needle drop.