You have a whomping big case of euonymus scale!! An insect, not a disease. It's hard to treat successfully so many gardeners just opt to get rid of the plant. Google for control options if you wish to try.

Can't say what might be up with the photinia without photos but photinia leaf spot is extremely common and a reasonable guess :-)

Thanks. Do you suspect it's worth the effort to try and save the plants? It would be a shame to start over fresh since it's a row of established plants. Separately, is it reasonable to suggest that the paint dust nearby may have weakened the plants?

I think I was wrong about the photinias. They're a bit dry from the summer heat here (Zone 9), but I suspect they're fine.

If all the euonymus look as bad as the photo, seriously........I wouldn't bother. E. japonicus is very prone to scale in many parts of the country so any efforts to control may be only temporary at best. And no, the paint had nothing to do with it :-)

Thanks for the feedback! Would it be risky to replace these plants with new euonymus?

Somewhat :-) The new plants are just as likely to contract scale at some point in time.

Maybe look for some other broadleaved evergreen shrub that is not so inclined to insect issues

Thanks. Do you suspect it's worth the effort to try and save the plants?

===>>>>

NO!!!! .. this is the sole reason.. over the years.. i got rid of all of them in my garden... and tried to convince everyone who owned one.. to get rid of them.. and counseled peeps to never buy one ...

sooo.. in that light.. there are too many options out there that are not Es ... so dont go replacing them with the same thing ...

ken

and for a shiny penny.. i will tell you how i really feel about them ...

@ken_adrian Adrian MI cold Z5 Since you're here and I happen to have a shiny penny :) any suggestions for euonymus alternatives in zone 9? I like that they're a nice, dense green shrub that isn't too flowery. They make a nice backdrop in my backyard.

Pittosporum tobira, Choisya ternata, Eleaegnus 'Gilt Edge' (a euonymus look-alike!), Lonicera nitida.

Those are great - thanks!