Dahlia imperialis in Australia
Paul Tyerman (Sun, 23 Oct 2005 15:55:31 PDT)

At 11:50 PM 23/10/2005, you wrote:

Howdy All,

Apologies for delays in contributing to this discussion. I am barely
using the computer at the moment due to continuing hassles with my
Chronic Fatigue. If you're expecting and answer from me and you
don't get it within 10 days please send me a gentle reminder as it
means it got lost in the flurry of emails I get when I DO log in. <grin>

Re Dahlia imperialis..... Just to let people know.... here in
Australia we have single and double mauve (or pink if you'd like to
call it that), plus single and double white. That is at the very
least. I have heard of other colours rumoured. The basic mauve-pink
"species" that we have here can easily flower at 6 metres tall,
making a stunning structural addition to the garden. I do not grow
the double mauve myself, just seen it offered via mail-order. The
single and double whites unfortunately rarely flower as they start
flowering a month or so later than the single mauve-pink, which
normally only just starts flowering before frosts.

I an intrigued that no-one has mentioned Dahlia excelsa, another
valuable "tree" dahlia.... which is basically a similar scale (gets
to at least 4m without hassles, although it does like a bit of extra
summer water to keep it happier) but flowers a couple of months
earlier. With the normal mauve-pink single one we get a few flowers
before frost (it usually starts flowering early May) but the excelsa
starts in March so it is well and truly in flower before the frosts
start. It has a slightly smaller flower than imperialis, and is more
of a dark pink with darker throat. There have also been hybrids made
(here in Australia at least, but I would assume elsewhere as well)
between the "tree dahlias" and the normal dahlias..... these are
producing much taller varieties that start flowering before Christmas
(i.e early summer) but can reach 2 to 3 metres tall. I for example
have a hybrid in my garden that produces semi-double orange/apricot
flowers for most of summer, but on a plant that is 2.5 to 3m
tall. These hybrids do unfortunately need staking as they do not
(well the coupel I have seen anyway) have not inherited the much
thicker stem of the imperialis/excelsa parentage. I am sure though
that some of the hybrids HAVE inherited that particular trait.

I just thought that some of this information might be useful as some
of it hasn't been mentioned. I have no idea whether they have
cultivar names, but before jumping to do that please find out whether
names have already been registered somewhere else in the world and
maybe try to name them the same thing. Makes identification MUCH
easier. The basic Mauve-pink and the double white at least have been
around for many years here in Australia, so I would verify when
Strybings got theirs and as to whether they bred it themselves or
just imported it from somewhere else before starting naming them
based on the assumption they came from Strybings. They may very well
have originated there, but definitely worth checking that for sure
before assuming.

Anyway, again my apologies for taking so long to contribute this. I
just don't use the computer much at all any more, so please also give
me some leeway with typos etc too! <grin>.

Cheers.

Paul Tyerman
Canberra, Australia - USDA Zone Equivalent approx. 8/9

Growing an eclectic collection of plants from all over the world
including Aroids, Crocus, Cyclamen, Erythroniums, Fritillarias,
Galanthus, Irises, Trilliums (to name but a few) and just about
anything else that doesn't move!!