Dahlia species...TOW

Paul Tyerman ptyerman@ozemail.com.au
Wed, 16 Jul 2003 07:13:45 PDT
At 12:48  15/07/03 +0000, you wrote:
>Dear all:
>              The first thing of interest in Dahlia species is how different 
>than those of garden Dahlias their flowers are . In fact, they always look 
>like daisies (some like Coreopsis, some like Tithonias) and from a distance 
>Dahlia imperialis flowers look like Clematis.


Very true.

>And Paul, Dahlia imperialis is not a short day plant here. It is obviously a 
>matter of temperatures as it flowers for a long period in summer and autumn. 
>When grown in greenhouses it starts flowering in spring and does not stop 
>until late autumn. I find a great drawback in “tree” Dahlias and it is that 
>they can be torn to pieces by wind and it is not always easy to find a 
>sheltered place for them in every garden.

It was Uli who suggested the short day, not me.  Here in Canberra what we
grow as imperialis (the big open "spiedry" mauve flowers that resemble
clemtis) open in late autumn just as the frosts are about to hit.  We
always used to use it to forecast when a frost was due as for 6 years
running the first frost hit within 4-6 days of the first flower opening.
Was very frustrating.  This year we have had a very late winter (still
waiting in some ways.... VERY mild so far frost-wise) so it was teh best
flwoering I can remember.

The Dahlia excelsa opens in early autumn theoretically.  I have not had it
long enough to know for sure in my garden.  Hopefully next summer it will
be fully established so I shall know for sure.  The flowers are much
smaller, rounder and more "filled in" than the imperialis and are a darker
pink with a dark centre around orange stamen.

Do these descriptions match with yours Alberto?  It is so darn hard at
times to find out if what we have here in Australia as such-and-such
species IS actually that species or is something clsoe that is mislabelled.
 I probably have shots of both of mine if you would like to see them for
verification purposes.

It was fascinating to see the list of species too Alberto.  I had no idea
there were so many different species, but I had assumed there must be a few
given the huge variety that has been bred into the horticultural forms.
They must have come from somewhere originally to get teh vast differences
in types, although I realise that selective breeding accounts for the
majority of them.  Still very fscinating to see the list.  Thanks.


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

Growing.... Galanthus, Erythroniums, Fritillarias, Cyclamen, Crocus,
Cyrtanthus, Oxalis, Liliums, Hellebores, Aroids, Irises plus just about
anything else that doesn't move!!!!!

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