On 19/07/2019 08:30, Jeff Layman wrote:
With nearly all shrubs or climbers it is usually easy to tell if a
branch is still alive by stripping off a small piece of bark. If it's
green underneath it's alive, any other colour it's not.

But that "rule of thumb" does not appear to work with clematis. They
usually show a dull sort of yellow colour - never green - when I scrape
away a bit of bark. Yet they are alive and growing well above the
scraped point.

Is their internal structure different from other plants? If there are no
green leaves on the branch, how can you tell if that piece is alive or not?

Depends on the type, if its a later flowering sort and it is that
difficult to tell if its alive or dead I would cut it off anyway and let
it start again, bit more tricky with stuff like montana, there I may
wait until the following march and cut it down if it isnt coming back
into growth. Clematis stems are not long lived so you are better off
getting rid of them if they are showing signs of distress, and regularly
pruning out stems on a rotational basis so none get too old.
But you are right its not easy in winter say to check whether a stem is
good or not

--
Charlie Pridham
Gardening in Cornwall
www.roselandhouse.co.uk