"David Hill" wrote a most itneresting post
about tree dahlias

David I've long wanted to have a tree dahlia and was finally given a number
of cuttings in the pst 6 months. I have one growing in a pot in my sun room
and it's now topping 6ft. All danger of frosts here in the sthn hemisphere
should now be over and I can finally plant it out. I've found an
appropriate spot where there is limited danger to it from strong winds but
can you provide some hints on how to grow this plant for optimal perfomance?

I have no idea what sort of tree dahlia it is. Probably whatever the most
commonly availble one would be.