On 08/11/2012 05:07, Farm1 wrote:
"David Hill" wrote in message
...
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?

Australia, but that is no help either given it's size. Cold winters down to
-9C, 40C in mid summer for about a week, between 28-36 inches of rain per
year, considered to be temperate.

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 squinted at all the pics in your first post and I really can't say with
any certainty. It looks more like the leaves on the pic 2 further on from
the one that shows your hand. The leaves in the first pic you mention seem
to be too glaucous. In all honesty I really can't say which pic they look
most like. If it's any help, there are in clusters of 5 individual leaves
on each major leaf. Sorry can't put my hand on my Hort. dictionary to use
more correct terms.

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.

The one I have growing was from a stem cutting but the other cuttings I have
in potting mix in polystyrene boxes have done nothing so far.

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.

Ah. I might have a chance of some flowers if heat is a requirement.

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'm planting this one on the protected side of a windbreak that also has a
6ft high fence made of shade cloth, so that wind can filter through that if
it gets thorogh the wind break, but I shall certainly give this one a stout
stake in accordance with yoru advice.

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.

Excellent. Thank you. Drainage is good and I will certainly plant at that
level. Do you fertilise yours regularly or give them any special treatment
during the growing season?


If you had it from a stem cutting, why not ask the person who gave it to
you what they do.