"Bowman" wrote in message
...
Can they be propagated by layering (or by air-layering) from the green
'twirly' above ground vine-bits, whatever they are called ! at this time
of
year ( SW England )

thanks.

They are very easy to propagate from short internodal cuttings (set of buds
at top but not at bottom) layering and root division, indeed after you have
had one a couple of years preventing it spreading is likely to be a higher
priority than propagating it!

--
Charlie, gardening in Cornwall.
http://www.roselandhouse.co.uk
Holders of National Plant Collection of Clematis viticella (cvs)