Russian Sage Question

I have a Russian Sage that is large. This summer I have watered it as usual, but we have had a lot more precipitation than normal. I was gone 2 weeks, and I'm not sure how much my caretaker watered it, but I would assume he watered it correctly, as everything else is looking good. About 2 weeks ago, I noticed that the flowers on some of the branches in the middle of the plant had dried up, and foliage was dried up, too. I've never noticed such this early in the season before. The outer stems are floppy on the ground, but covered with beautiful purple flowers. Do you think the plant has gotten root rot, and is there anything I can do to help it? Do you think it will come back next spring. It is a very large plant. I live in Zone 5/6/7, Salt Lake City. I know these plants don't like much water. When it was tiny, and just first planted, I didn't know that and gave it a lot of water. The leaves became yellow, and I thought I would lose it, but it recovered and became giant. I've had it about 8 years. My other two Russian sages are much smaller and don't show any dried up flowers/leaves. They don't get as much sun. Should I cut off the dried up branches now or wait until the spring? Some of the branches that have dried up flowers and leaves look green (the stems). Thanks for all opinions.

You know, around here Russian sages are as tough as nails. Mine never get watered by me, sometimes get whacked off to a stub, halved by a shovel, you name it. The only way I have killed one was to dig it up, pot it, put it under the deck where the rain couldn't reach it, and forget to water it forever. And, it came back from the space I dug it up from.
It may just be the normal cycle of the leaves there in the middle to dry up. If there are still green stems, you can cut them off, or prune them back. I bet they will bounce right back.