Hi,
This is the nature of your evergreen Armandi. Some shade in your position or cold drying winds in winter time will give you ugly brown leaves hanging on the plant for a long time. Try to find a better position for it or replace with a better clematis. What do you like the most in your Armandi evergreen leaves or fragrant flowers? If it is flowers there are many other fragrant clematises like Montanas, Rehderiana, Crispa, Baleatica.
