Did you realize that coniferous tree needles change color in the autumn too, just like deciduous trees? Homeowners are often alarmed when their evergreen trees start to drop needles. Although most conifer trees are considered to be “evergreen”, their needles don’t live forever. What makes them “evergreen” is that their leaves persist more than one year before falling. Since new needles are added every year, there is always an overlap between green needles and those that are due to fall.
Conifers will shed older inner needles each autumn after they turn yellow, brown or reddish-tan in color. Sometimes this natural process is very subtle and goes unnoticed because only the inner most needles area affected. Pine trees can hold their needles for 2 to 5 years, sometimes more, depending on the species. Spruce trees can hold onto their needles longer than pine trees do, approximately 5 to 7 years.
One evergreen tree that is very noticeable as it loses its leaves in autumn is Eastern White Pine. This tree only holds its needles for two years, which leaves less growth at the tip of branches to hide the needles as they are shed. Combined with the soft texture and open structure of the Eastern White Pine, autumn needle shed is very easily seen.
So, if your tree begins to shed — remember not to panic! Autumn needle drop is a natural condition and is not a sign of disease or insect infestation. However, any factor that increases stress on evergreen trees will intensify the needle drop in the fall. Stress factors include: drought, herbicide injury, root damage and insect or disease damage. Natural needle drop occurs only on the inner needles. If entire branches or needles at the tips of branches are dying, then something else may be occurring. A sample of the affected branches should be submitted to your local Cooperative Extension office for diagnosis.
Believe it or not, there are actually a few types of conifers that shed all their needles EVERY year. These deciduous conifers include Larch, Bald Cypress and Dawn Redwood. The Larch with its golden yellow and the Bald Cypress and Dawn Redwood with their bronze hues will add great beauty to any fall landscape.