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Conifer Trees in Denver During The Fall

You may notice the appearance of brown needles in your various pine trees and begin to worry, but is this phenomenon something normal or cause for concern?

Every fall, people all across the country enjoy the changing colors of the trees. The explosion of color that occurs is nothing short of a natural miracle. The fact that this happens every year, helps us mark various events in our lives. What many people do not realize is that conifer trees also go through foliage changes in the fall, but it’s not as obvious. The interior browning of the needles on Spruce and Pine trees is a natural physiological process in conifer trees that many people mistake for signs of sickness or stress. This process is known as “Fall Needlecast”, and is perfectly normal, so don’t worry.

Normal Fall Needle Cast
Normal Fall Needle Cast

Conifer trees expend a great deal of energy to produce their needle tissue. It is for this reason that these trees retain this tissue for more than one season. It is crucial for the plant to get the most return from their needle tissue while it is still efficient and productive. As new needles are produced by the tree each year, older needles become shaded and inefficient. The tree uses the changes in temperatures and daylight to trigger the browning and needle drop. Through this process the tree can focus its energy on maintaining needle tissue that provides the largest amount of energy production.

There are stress related reasons that force conifer trees to shed needles so it is important to closely examine your trees. Normal fall needle drop in pines and spruce trees should always be relegated to older needle tissue, and should not include the current year or previous year growth. If you have questions about what you are seeing, be sure to call one of our Arborists who will be happy to help.