Manzanitas dying from ground up
See photo. All of my manzanitas are exhibiting leaf spotting and eventual leaf death which starts at base and spreads gradually upward on the plant. Dark brown powdery mold appears on some dead leaf surfaces. Affected types include "Austin Griffiths" and "Warren Roberts". Possibly related, my prostrate A. uva-ursi appear to die rapidly. Pretty clearly a fungus but I'm not sure which one or how to treat. Thanks!
Fungus on manzanitas are best dealt with by removing infected leaves and debris. Their are 5 or 6 common fungi and would require a lab analysis to ID, an unnecessarily expensive task in our opinion.
Here is a likely cause and recommendation.