I'll be interested to see what others say because it looks like normal fall change to me.

It's just rose canes reaching old age. I usually try to prune off one or two of these each year at normal pruning time to encourage the plant to throw new basals.

Otherwise, fertilize with Geritol.

Yes, just old age on those canes. The 2nd one looks like it has some stem canker at the old cut where you have dead (grey) tissue then the black then the red line. That one might have gotten pruned in a cool, damp spell of weather.

Professor R. here in So Cal, the healthy canes don't change color much in Autumn--not cold enough.

Canes that are several years old become gray and barky. Green canes are one or two years old (most varieties). In between, there is a transition where the cane may turn various colors, so don't be quick to take alarm at color changes. If a cane proves unable to support vigorous lateral shoots with good flowers, there is something wrong.

As Hoov notes -- Southern CA doesn't get much color change in plants. I have some roses that are SUPPOSED to get fall foliage, but even they rarely do.

OTOH, during our long, cold, dank spring (which now in memory seems pretty wonderful)we did see some downy mildew crop up, and at least one of your canes shows what may be the marks of that fungal problem.

This fungus lives within the tissue of the plant, and plant tissues are killed by it. You see it on leaves, but also on canes. The marks are purple-to-black, and as that tissue dies, it becomes silvery-gray -- dead. In severe conditions, it goes all the way to the roots.

I used to have some diagnostic photos of downy mildew damage on leaves and canes, but I'm darned if I can find them, now. Below see a link to an extensive article on it.

Jeri

Here is a link that might be useful: DOWNY MILDEW

I am interested in any advice as well. My landlady has yellowing canes on every rose bush on the west side of the house. I am concerned her "gardener" has spread some disease, or some previously dormant fungus or virus has taken hold in the aftermath of a long, hot, late summer. I have had roses in this area for 40 years, and I've never seen ALL of the plants in one location have yellowing canes. We are in the inland valleys of San Diego, and had more humidity with heat than usual. Also, leaves are not showing disease, just canes. Thank you.