UPDATE - JUNE 26:
Carson City staff, working with state and local plant health experts, have identified key causes behind the decline of trees and landscaping in various public rights-of-way, parks, and streetscapes across the city.
The inspection team included two independent ISA Certified Arborists, an entomologist from the Nevada Department of Agriculture, a municipal urban forester, a University of Nevada Cooperative Extension horticulturist, and a licensed pesticide contractor.
According to their findings, several factors are contributing to the decline:
- Heat stress:Â Prolonged high air temperatures and the widespread use of rock mulch have raised soil temperatures. Drought-intolerant trees, such as Red Oaks, were especially affected, showing visible signs of stress and poor climate adaptation.
- Herbicide exposure:Â In some locations, trees and shrubs displayed symptoms of herbicide damage. These chemicals are used to control invasive weeds, which can otherwise outcompete healthy plants. Typically, herbicides are filtered by rain and snow in winter, but due to a light winter, concentrations may have remained elevated.
- Insect infestation:Â Scale insects and powdery mildew were observed, especially in trees already weakened by environmental stress.
- Irrigation issues:Â Ongoing inspections revealed irrigation breaks, pinched lines, and outdated equipment, which have led to inconsistent watering. Staff are actively making necessary repairs and replacements.
- Overplanting and competition:Â Some trees were planted improperly, and unsuitable species were placed in areas that were overplanted, causing excessive root competition for water and nutrients.
The city has partnered with a licensed tree service company to remove trees deemed nonviable.
Most of the estimated 250 trees slated for removal are located in the Silver Oak and Northridge neighborhoods.
Trees still showing signs of viability will remain in place and continue to be monitored.
Moving forward, the city is coordinating with the University of Nevada Cooperative Extension horticulturist to conduct soil sampling for chemical residue.
Once sampling is complete, the affected areas will be flushed to reduce contaminants.
Staff are also reviewing herbicide application practices and irrigation schedules.
Adjustments have already been made to improve watering consistency.
Landscaping methods may be updated as well, such as replacing rock mulch with organic alternatives like wood chips to help lower soil temperatures.
Ongoing monitoring will guide future tree removals or replacements. A fall replanting plan is currently in development.
Residents who notice signs of tree stress or decline on their private property are encouraged to contact a certified arborist. To find one, visit treesaregood.org/findanarborist or contact the University of Nevada, Reno Cooperative Extension at extension.unr.edu.
ORIGINAL STORY - MAY 30:
The Carson City Department of Parks, Recreation and Open Space has been fielding reports of tree decline at multiple locations across the city.
The department is actively investigating the reports, and so far they've uncovered that there may be a potentially invasive species or tree disease affecting the health of several tree populations in the area.
The City is working with experts - including certified arborists, the University of Nevada Cooperative Extension and pest control contractors - to determine the severity of the issue so they can move forward with an appropriate response.
If you see any tree stress or decline on your own property, you may want to contact a certified arborist - to find one, visit the Trees Are Good website, which is the International Society of Arboriculture's list of credentialed resources.
Alternatively, you can reach out to the University of Nevada, Reno Cooperative Extension at their website.
