Without a doubt it is the dreaded photinia leaf blight - a very common problem here in the PNW, so much so that these shrubs are no longer carried by most local retail nurseries. In fact, it is difficult to find a planting of photinias here that is NOT infected....a few single specimen shrubs may be OK but generally, any sort of hedging will be infected to some degree.

Yup. And there are hundreds of them at this site. Boggles the mind that the landscape planners and architects choose to use these plants that do so poorly, so consistently. Any remedies suggested to treat this are just not viable at this scale. Thanks.