Anyone?

Cold or temperature fluctuations could explain a lot of discolored leaves this time of year. I bet the new leaves grow out normal.

Agree Sheila may be right, regarding cold.

I first came here, about 6 years ago, seeking explanation for why some new spring foliage on Purple Pavement had partially blackened. I had initially rejected freeze damage, thinking hybrid rugosas were very resistant to it. Aquaeyes pointed out their cold resistant reputation applied to the bush’s ability to survive cold, and not the foliage’s tolerance of it.

In the end, I decided that was the cause.

Thank you. I'll be keeping an eye on it. If it were just cold, that would be great actually.