Your cedar tree is not dying

Normal, seasonal change in Western Redcedar trees

Story and photo from WSU Extension Puget Sound Forest Stewardship

It's that time of year when the western red cedars (and all the other conifers -- but it's most visible in the cedars) do their fall housekeeping. Trees that look like this are NOT dying. 

Just like their deciduous counterparts, evergreen conifers shed foliage in the fall. However, they are only shedding their innermost foliage, which is their oldest foliage. 

This foliage may be several years old. Over time, the photosynthetic productivity of foliage decreases due to shading from newer foliage, internal wear-and-tear, and dirt that accumulates. 

Abscission of the older foliage occurs when it costs the tree more to maintain them than it’s getting back via photosynthesis, or if the tree would obtain a net gain in productivity by transferring resources from the older needles to the newer, more productive needles. 

When it is time for the abscission of older foliage on evergreen conifers, the foliage will turn color and fall off the tree, similar to what happens to the foliage on deciduous trees. 

This is a normal part of conifer growth which will resolve itself with the changing of the seasons. 

This seasonal phenomenon tends to be highly visible in western redcedar because of the nature of its foliage; it has overlapping scales for foliage instead of individual needles. Thus, instead of small individual needles turning color, entire branchlets turn color.