- Why are my cedars dying?
Without specific information there could be several reasons but, the most common reasons are either climate change or disease. With either, the problem started a year or more ago.
Climate change has brought drought to the region. Cedars do not have a deep root structure, happily living with high precipitation rates from early fall through late spring. Come summer they can live with intermittent rain. The last few years we have had low precipitation rates in the winter & little to no rain in the summer. This stresses the trees to the point of death from lack of water. If the tree doesn't die it will be susceptible to disease.
Diseases affecting Cedars are the Cedar leaf blight. It is caused by the pathogen Didymascella thujina which affects only western red cedar (Thuja plicata) throughout its range in British Columbia. In addition, the Cedar bark beetle and juniper scale can affect cedars. At the earliest sign of trouble reach out to a certified arborist for help.
Sources:
https://botanicalgarden.ubc.ca/what-is-the-root-cause-of-yellow-cedar-decline/
https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www2.gov.bc.ca/gov/content/industry/forestry/managing-our-forest-resources/forest-health/forest-pests/foliar-pathogens/cedar-leaf-blight%23:~:text%3DCedar%2520leaf%2520blight%2520is%2520caused,South%2520and%2520West%2520Coast%2520Regions.&ved=2ahUKEwiBz_ixhuODAxXIGTQIHVpvAL0QFnoECBQQBQ&usg=AOvVaw2gPnus3fg9-gEU9v7FCADV
https://www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/agriculture-and-seafood/animal-and-crops/plant-health/dying-cedar-hedges.pdf