This is a public-interest archive. Personal data is pseudonymized and retained under GDPR Article 89.

Re: Dahlia imperialis/more info please]

Hi Sean,
Just a question about Dahlia imperialis setting seed. I understand that
some plants don't set seed unless  the climate is similar to what they're
used to (could this be special pollinators?). Dr. Baker of UC Berkeley
pointed out that Tibouchina is one such plant, which flowers in our San
Francisco Bay area but doesn't set seed because it is too cool here.
Elly Bade


On Fri, 29 Aug 1997, Sean O'Hara wrote:

> >From: connie hoy <bmprc@micron.net>
> >Subject: [Fwd: Re: Dahlia imperialis/more info please]
> >Sender: owner-medit-plants@ucdavis.edu
> >Date: Wed, 20 Aug 1997 23:23:00 -0700
> >
> > Hello to Dave and all,
> > I twice have purchased a "tuber"of this intriguing plant and am ashamed
> > to say I am feeling inadequate to the challenge..First of all the
> > "tuber"is actually more like an old piece of wood that has no visible
> > eyes whatso ever(nothing like a regular Dahlia).I really dont know if
> > there was  life in the first one (it showed rot early on)as it never
> > sprouted any growth at all.
> >
> > The grower sent me a replacement, promising to send more detailed
> > instruction but forgot to do so.This one looks slightly more hopeful but
> > the one thing he did tell me was that in my climate it would require a
> > VERY large container indeed (to winter over).This I can do but not even
> > sure as to planting depth ,etc.When I read you had a cutting couldnt
> > help but wonder if thats the reccomended/easier method of propagation.
> >
> > Does anyone know how long the tuber can be maintained without planting
> > it?Planting depth?
> > Any one that might know the best way to go on this one would be very
> > appreciated.
> > Regards,
> > Connie Hoy
> 
> Hi Connie -
> 
> What you are mentioning as a 'tuber' I think is actually a length of
> stem (i.e. a cutting) - the most common mean by which this Dahlia is
> propagated.  The plant does make tubers more typical to other
> Dahlias, but quite giant in size, making their shipment somewhat
> expensive.  I know this because I once dug out an old clump of these
> from an abandoned house scheduled to be bulldozed (It took 4
> days!!!)
> 
> To propogate Dahlia imperialis from a stem length, place the stem on
> its side, buried halfway up.  Keep moist but not soggy, and in
> bright shade and out of drying winds.  People often root these
> outside under a lightly branched shrub, in a windless corner. (if
> your climate is appropriate).  You make also do this in a greenhouse
> affair, or a cool window in the house where humidity is not too low.
> 
> Can say I've had to learn the finer points of this species
> propagation, since they are common in old gardens and there are
> often people wishing to remove them to plant something else.  I've
> seen 4 clones - the standard single lavender pink, its double form,
> the white single, and its double.
> 
> Personally, I like the single flowers which are produced in large,
> branched clusters, facing down like lampshades.  Big, overblown,
> fancy double Dahilas have never appealed to me.  The Double forms of
> D. imperialis are interesting and have a decent shape (also smaller
> than most Dahlias) but they have the undesireable habit of hanging
> on in death, quickly spoiling the display of successively opening
> flowers in the highly placed panicles (making it difficult to
> dead-head).
> 
> I have also never seen seed produced from these plants.  Perhaps
> they are self-sterile.
> 
> As far as overwintering, it is best for these plants to stay in the
> ground over winter - they are too big to manage otherwise and in a
> container, flowers would likely be sacrificed.  Ther could possibly
> make a marvelous foliage display (almost better than the flowers).
> I've had leaves on this plant up to 4ft across, with hundreds of
> leaflets (tri-pinnately compound) - just wonderful!  The best
> flowering come on plants which can overwinter the tree-like stems
> and resprout from these the following spring.
> 
>  Sean A. O'Hara                     sean.ohara@ucop.edu
>  710 Jean Street                    http://www.dla.ucop.edu/sao
>  Oakland, California  94610-1459    h o r t u l u s   a p t u s
>  (510) 987-0577                     'a garden suited to its purpose'
>
References:
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index