
A tree or shrub is considered an evergreen if their leaves persist more than one year before falling. This includes conifers like pine, arborvitae, spruce, and juniper. The needles of evergreens shed in late summer or early autumn. The natural yellowing of older needles, those towards the center of the tree, occurs uniformly from the top of the tree to the bottom. Needles at the tip of each branch (the younger needles) stay green. Since the younger needles are still green and healthy in appearance, then you can be certain this is normal and nothing needs to be done. New needles are added every year, so there is always an overlap between green needles and those due to fall. In most years, gardeners may never notice this leaf drop as it occurs gradually over a long period of time. In some years natural needle drop occurs in a short period of time making for a striking display but, some may fear they are losing the tree. Rapid leaf drop has been triggered by weather this year and should be no cause for alarm but if you fell your plant is in danger please contact an Aspen professional.