Western red cedars show stress of climate change

The lush, towering presence of western red cedars (Thuja plicata) in Washington state has been a hallmark of the region's natural beauty and ecological health.

However, these majestic trees are facing an unprecedented threat. Urban areas like Mount Vernon, Burlington and Anacortes are witnessing a troubling phenomenon: the dieback of western red cedars. Drought mitigation planning is essential in preserving this valuable community resource as long as possible.

Western red cedar dieback, primarily driven by drought and rising temperatures, is becoming increasingly common in urban landscapes. Red cedars struggle to survive in the changing climate as these environmental stressors intensify. Citizens in Skagit County have noticed dieback and alerted local officials. City parks departments are monitoring the health of groves in Mount Vernon and Burlington and observing that dieback is not currently a problem. However, it has occurred in Little Mountain Park as recently as five years ago.

To fully grasp the severity of this issue, it is essential to understand the historical significance of western red cedars. These trees have long been a symbol of stability and endurance, thriving in the Pacific Northwest's unique climate. Their decline marks a significant shift, highlighting the urgent need to adapt our urban forestry practices to the realities of climate change.

Washington State University (WSU) has invested considerable energy and resources in the observation and study of western red cedar dieback in Washington via their WSU Extension Forestry division. Working from the hypothesis that red cedar dieback is a consequence of the region's recent drought, WSU has launched the Forest Health Watch to keep track of dieback occurrences. To participate as a citizen scientist, access their website at: foresthealth.org/redcedar and report the dieback. Your information will help confront the looming disappearance of these giants in our midst. Access to a detailed map of citizen scientists reports is also provided. The website also provides multiple links to research on identification, biology, ecology, distribution, ethnobotany and relevant pests and diseases.

The dieback of western red cedars is a pressing issue that demands our immediate attention. By understanding the causes, implementing practical solutions and fostering community involvement, we can take meaningful steps to protect these iconic trees. The best action today's gardeners and homeowners can take to prevent red cedar dieback is to keep the soil around their trees weed-free and mulched and to discourage heavy foot traffic.

To read the full Ask a Master Gardener blog post and learn more about how you can contribute to the preservation of western red cedars, follow this link to the Skagit County WSU Extension Master Gardener website at www.skagitmg.org/western-redcedars/. Together, we can make a difference in safeguarding our urban forests' natural beauty and ecological health.

Sonja Nelson is a Skagit County WSU Extension Master Gardener Class of 2009.

Questions about home gardening or becoming a master gardener may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; 360-428-4270; or www.skagit.wsu.edu/mg.