"Red tips" is what we've called them. I think you should read up on the fungus issue so that you can be proactive in controlling/minimizing any outbreak.

Take a look at this link and then search for others. This one recommends good spacing, no overhead morning/evening watering, etc:

Space plants to improve the air movement around the plants and promote rapid drying of leaf surfaces. If it is necessary to irrigate the plants, do not wet the foliage or irrigate in midday to reduce the period of time foliage remains wet. If possible, remove fallen diseased leaves. Do not water or fertilize plants any more than necessary to avoid promoting excess new growth. Also, reduce pruning during the summer which promotes continual new growth. Severely defoliated plants may need to be pruned heavily to have a small, easier to spray plant, to reduce the source of spores and improve air movement.

It also provides fungicide recommendations.

Here is a link that might be useful: Entomosporium Leaf Spot on Red Tip

Thanks for the info and link. Guess prevention all boils down to improving air circulation, and sufficient drying.

Yes, which doesn't support the concept of using them as a dense hedge, but if you're willing to give them a little room between plants you could do it.

Good luck, they can be really beautiful when done right.

It is also a climate factor - humidity will have an affect as well. Here in the PNW, photinia leaf blight (Entomosporium) is just as much a problem as it is in the hot and humid south, however our humidity is centered in the late winter/early spring months and there is relatively little summer heat to speak of. Areas that are humid and warm during the late spring-summer months will certainly be at risk for the disease.

Yes, when I heard about the need for ventilation, I thought about the idea of spacing the photina somewhat apart between adult specimens (allowing for free movement of air). That's exactly what I'll do. My climate is very damp and wet (and warm)in summer so I guess I was just lucky so far. Thanks for the advice!

Occurrence still somewhat sporadic in this area, also have the impression specimens that are less green and healthy in the first place are more dramatically affected. However, a comparatively old one in the Camano garden went to pot soon after being infested and was cut down. Re-growth has not been vigorous, as though the leaf spot infestation really knocked it for a loop - but maybe it picked up another problem, like root rot about the same time to produce a debilitating syndrome.

Anyway...if there is much leaf spot in your region I would caution against depending on photinia for an architectural use (such as a hedge).