Re: Prostanthera length of flowering?

P. rotundifolia and P. ovalifolia both tend to be
rather ephemeral bloomers here in the SF Bay
Area(Zones 9/10) as well.  I have never had either
bloom for much longer than 6 weeks, usually in late
spring/early summer for me.  I have never had any
repeat bloom at other seasons.  There are several
other Prostanthera species grown at UC Santa Cruz
Botanic Garden that do have extended bloom periods,
but are also more subtle/less prolific while in bloom.
 P. lasianthos is a larger growing more tree-like
species with larger more leathery foliage and an
extended summer long bloom season, but is not covered
in bloom as is P. rotundifolia.  I also had a dwarf
groundcover species with an extended season of white
flowers and very deep green foliage, but can't
remember the species, which I had also purchased at
UCSC.

If you are looking for another summer blooming shrub
companion for the Tibouchina urvilleana, you might
consider Duranta stenostachya or D. repens.  Neither
one is likely to do well year round outdoors in your
zone, but both do very well as a container grown green
house/house plant flowering shrub with a very long
bloom season, and similar flower/foliage and growth
habit to the Prostanthera.  You might consider this as
a plunge pot specimen to be relocated into the
greenhouse for the winter in zone 8 conditions.  D.
stenostachya has been hardy for me down to 24F, and is
in massive bloom since April, continuing into November
as long as I remember to keep feeding it to promote
flowering(it is competing with the dense roots of a 30
year old Pittosporum tenuifolium hedge).  The foliage
is similar to a Boxwood with an arching habit and very
dense growth, and is attractive even without bloom,
but tending to lose foliage with colder/wet winter
weather.

Trachelium caeruleum might be another summer blooming
perennial to consider as an accent to the Tibouchina,
or Francoa sonchifolia.  Dianella intermedia would
also combine attractive long lasting deep purple
berries just now coloring up and lasting over a two
month period.  All of these will handle some limited
summer drought,(as in 10~14 days between waterings in
my cool Berkeley conditions), but bloom better with
regular periodic summer watering, and do well for me
with twice weekly irrigation and heavy root
competition from trees.  Plectranthus zuluensis is
another tender perennial with light lavender showy
flower clusters blooming in light shade to full sun
almost year round here, and can reach 5 feet in height
or be kept trimmed to 2.5 feet.  It can be kept over
winter as rooted cuttings, to be replanted out in the
garden once frost is past.  A great plant for cooler
maritime climates as it does not require  summer
warmth to start blooming in early spring, and will
continue blooming into winter here as long as it
doesn't freeze.  I also have Acanthus spinosa var
spinosissima gowing in these same conditions, and it
remains in bloom all summer long. 


--- Diane Whitehead <voltaire@islandnet.com> wrote:
> How long does Prostanthera rotundifolia bloom?
> 
> Mine were covered in flowers earlier in the summer,
> but there hasn't 
> been a flower since.  I had hoped that the masses of
> small purple 
> flowers would be a good companion to the large
> purple flowers of 
> Tibouchina, which is flowering now.
> 
> Maybe I will just have to be happy with the lovely
> scent whenever I 
> brush against the mint bush's leaves.
> 
> 
> -- 
> Diane Whitehead  Victoria, British Columbia, Canada
> maritime zone 8
> cool mediterranean climate (dry summer, rainy winter
> - 68 cm annually)
> sandy soil
> 


__________________________________
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software
http://sitebuilder.yahoo.com
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index