It looks like winter die back to me. I've got the same problem. You might have to cut some canes all the way down to the bud union. If you have a couple of canes on each bush that are healthy, feel blessed. It was a tough winter for a LOT of plants (not just roses) this year.

The yellowness of the foliage looks chlorotic, which if there is any iron in your soil at all, the foliage will green up as soon as the soil warms up more. In colder soil, roots have a harder time accessing the iron that is there in the soil.

"Iron chlorosis is known to be aggravated by cool soil temperatures and conditions that restrict air movement into soil: plastic sheet mulching, compaction, and water-saturated conditions. "

In warmer soil, the roots can make use of the iron.

Yellow canes--those are usually on their way out. The plant looks like it still has some good healthy areas, so nothing to get too worried about yet.

Chlorosis is rather complex--no "instant" cure, but no need to to jump on and Do Something About It today. Read about it and get a good understanding of your soil and when/if it happens, so you can develop a long term correction, if necessary. There are some good articles from State agricultural sites and universities.

Here is a link that might be useful: one example article on chlorosis U of Utah

This type of growth happens in spring on canes that may have looked ok at time of pruning, but in fact they were winter damaged and still left on the plant after pruning. Just prune the canes down to where you look like you have nice dark green and more vigorous growth and the rose will be just fine.

If you leave this on the plant, these leaves will eventually shrivel and the cane will die back to the point the rose decides it needs it to. It won't kill the rose, but it will rob it of some energy and look unsightly and you'll only end up needing to prune it away later anyways.

Thank you, very much for the input, all 3 of you. I now have a starting point of what to look for & where to go next, based on continuing symptoms. I really appreciate you all taking the time to help me out with this!

~ René

A few new things for me in this thread. I didn't know about the potential problems with plastic cover. Had not used it with my previous rose and see that I shouldn't. Also, had never heard of chlorosis. Yeah, this winter was brutal on just about all plants.

My first thought was cold damage too. I know when I've left cane that was marginal when pruning in the past. It almost always dies off anyway and I end up going back and repruning them. Now I just take off anything that looks iffy right from the start. It saves the plant from wasting energy on leaves that will not live and saves me from having to prune again.