I am sorry for this delayed reply to your gardening question as we are transitioning to a new Q&A system. I hope this reply is not too late to be of help.
Your plants are suffering from something in the root system. If a herbicide such as a weed and feed were used and if an extra amount was put on the side of those bushes showing the symptoms it could cause such problems. There is not cure for herbicide injury but time...if the initial poisoning was not too severe.
Another possibility is soggy wet soil conditions. If that area has a leaky underground irrigation line or water line, or if it is lower and stays wetter, this could be why those plants are so affected. The fact that the parts in late day sun are most effected is probably because the demands on those branches and leaves are greatest.
The problem you are seeing is not likely due to any disease since it affect those two unrelated plant species.
Thanks for the question. Please stop in again soon!
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