On 07/11/2012 00:22, Farm1 wrote:
"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.


The Southern Hemisphere is a large place, where exactly?
Does your dahlia look anything like the plants in the foreground?
http://s240.photobucket.com/albums/f...othertrees.jpg
D. Imperialis has very large leaves, as I have said I measured one the
other day and it was 37 inches long.
There are a lot of tree dahlias but Imperialis is the most commonly
grown variety.
I saw pictures of some well established "Trees" growing in Northern
India with snow covered mountains in the distance.
They can be grown from stem cuttings as well as from seed and ordinary
cuttings.
They seem to need a hot summer to initiate flower bud , buy don't flower
till the day length is falling, here and in the US of A it is normal for
them to be in flower in November weather permitting.
This year because of the very poor summer I have no flower buds formed
on any of my 13 Imperialis, where as D. Tenuicaulis has formed buds.
http://s240.photobucket.com/albums/f...caulisbuds.jpg
With both the flower buds form at the end of the shoots.
When planting out you will need a tall, strong stake especially if you
are in an area prone to wind.
I would rate them as very tender perennial, if frost free they will grow
on from year to year making a larger trunk and a "Tree", where there is
frost they will take the occasional light frost but will get cut back to
ground level by hard frost.
If the tuber is planted 6 or more inches below the surface, and you
cover with straw or similar in winter the tuber should survive outside,
provided it has good drainage.
David @ the rain free end of Swansea Bay.