Sacha wrote:

Well, if you haven't got the Dahlia imperialis, don't you think you should
try it in your garden and see if it hits its 14' stride!?

I bought one from Ian Cooke back in '96 when he still had his nursery
near Launceston. It reached just a shade under 12ft. by October and
then produced its terminal raceme of rather nondescript pink flowers.
They opened over several weeks, but autumn rains did them no favours
and having to scale ladders to view flowers that aren't worth the
climb din't really cut it with me. I though it might be knocked back
during that winter, but the stem proved hardy and off it went again in
the following year. It proved a big mistake not to cut it back,
because the plant turned into a monstrous heap. I didn't wait for
flowers and consigned it to the bonfire well before summer was out.

And did we give
you the wonderful Dahlia excelsa, David Hill gave us?

No, I did think about that because the flowers are worth the effort,
but there's not enough room here now. The dark /dusky leaved types
are more my 'thing' - hence my admiration for varieties such as
'Fascination' and 'Roxy'. The next 'biggie' in terms of impact has to
be 'Twynings After Eight'. A magnificent single white with the
blackest foliage imaginable. If you haven't got it, it's an absolute
must. Definitely on my list for '09