A couple weeks ago I asked a question about Clematis cirrhosa suckering.
Now I may know why.

This is a 10-year old plant which has spread well and partially covers a
large Ceanothus. I noticed yesterday that a lot of the top growth
appeared to be brown and dead, with only a fraction still with green
leaves. So I thought I'd cut out the dead stuff.

My usual test to see if anything is alive is to scrape the bark for a cm
or so. If it's green underneath, I assume it's alive. If not, I assume
it's dead. But the clematis was odd. I scraped a couple of stems
(about 8 mm in diameter) and they were brown. So I cut through them and
was surprised to see that the "heartwood" was green. Not only that, but
there were some green buds higher up on the cut stems when I pulled them
down.

So I'm leaving it alone for the time being. Maybe it'll recover; if
not, some of those suckers seem to have rooted now I've potted them up.

--

Jeff