Dahlia imperialis in Australia

Paul Tyerman ptyerman@ozemail.com.au
Sun, 23 Oct 2005 15:55:31 PDT
At 11:50 PM 23/10/2005, you wrote:
>         Since the double purple and double white Dahlia imperialis 
> seem to have
>come from Strybing, I am curious if they have been given cultivar names
>yet, or should one of us take care of that chore?

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>.


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!! 

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