In message , Pam Morris
writes
Clematis armandii is also evergreen, early flowering and scented, and
vigorous; would clothe your arch fairly rapidly.

Aren't clematis moody if you don't prune them just so and at the right
time?

I'm in SE London but postally in Kent. I'm on London loam rather than
chalk. I have a C. armandii growing over an arch quite close to the
house so it's probably protected a bit. C. armandii flowers in the
spring on the previous year's growth so you have to bear that in mind
when pruning it (prune it after it's finished flowering (and not later
in the year) for maximum flowers next year). It took a while to get
going but now it's very vigorous.

--
dave @ stejonda