Redder Western Red Cedars by Bengt Miller, Stewardship Coordinator

If you have been paying attention to the trees lately, then you may have noticed that they are getting ready
for fall. Trees have ceased their growth and are preparing for their leaf drop and dormant season. This
becomes particularly evident when deciduous trees shed their leaves in fall, sometimes with spectacular
showing of autumn color. While it is obvious that deciduous trees like alders, maples, and cottonwoods
lose their leaves in the fall, most people are unaware that evergreens (also called conifers) also lose
some of their foliage.
When western red cedars lose their older needles, it is called cedar flagging. It is most noticeable in the
late summer through fall as brown interior branches begin to appear. To those unaware this can look
disconcerting, as it appears the tree is beginning to turn brown and die. Fear not, this is a natural
process. It can be exacerbated by periods of drought, but is a natural process and does not harm the
tree. By the time spring arrives the dead needles have fallen to the ground and the tree appears all
green again.
As more and more people hear about the native cedars struggling in our area, many are paying more and
more attention to their arboreal surroundings. It’s true our iconic western red cedars appear to be
struggling with the local impacts from climate change, but not every cedar you see with some brown in
the canopy is dying. Drought stressed cedars turn brown from the top down and then from the branch tips to
the interior. Cedar flagging occurs from the interior of the tree outwards. The cedar sheds the older
interior needles while the tips remain green.
If you believe you have noticed this on a local neighborhood tree, keep an eye on it. Most likely the dead
needles and branches will fall during a heavy rainstorm or the first serious windstorm of the winter.
Then these branches will fall to the ground and act as a mulch for the surrounding forest. Older
generations of needles/leaves provide nutrients for future generations of trees, much like adult salmon dying provides nutrition for future salmon generations.