Calostemma purpureum
Jim Lykos (Tue, 07 Oct 2003 05:51:44 PDT)

Hi Jane and Rob,

Rob's growing conditions in Tasmania are probably the most comparable
with your own.
Complicating the information that Rob has given, is the very wide
distribution of this species in the semi arid and arid interior of the
Eastern states of Australia down into the southern part of South
Australia a span of over 1,500 miles. in the northern parts of the
distribution rainfall is heavy in summer, driest in winter , while in
the southern part of its distribution it faces winter rain and very dry
summers. Populations of this species have generally adapted to these
conditions - so that the NSW Calostemma's tend to go dormant during
early spring and then are revived and flower once a substantial
mid-summer rain storm occurs.
In South Australia, they will go dormant early in early or late spring
(soon after ground moisture dries up) - and they usually wait until the
first late summer storms or autumn rainfall before they flower- and
autumn flowering is the most typical flowering period.
In my own collection I also have found Calostemma purpureum from South
Australian to be the quickest to go into dormancy in dry weather.
As Rob mentioned its usually hot and dry soil conditions that initiate
hibernation, and hot wet conditions after a rest period that initiate
the flowering cycle. In your conditions they appear to have missed the
spring and summer heat triggers. In the Australian outback in Spring and
Summer it becomes really hot and dry - 30+ for at least 4 months, and
these conditions would be most approximated in some regions of Texas
and California. To optimise flowering I think it would be best to stop
watering them in mid spring, allow the pots to have some direct
sunlight during summer and allow watering by natural rainfall or
restart watering in the last month of summer.
Calostemma luteum on the other hand is much more associated with the
flood plains of the interior of Eastern Australia, and grows more
commonly in fertile clay flats. It is even more responsive to rainfall
in breaking its dry dormancy periods - and it typically flowers in mid
to late autumn and in early spring ( April, May and September).
Good Calostemming

Cheers

Jim Lykos
Blue Mountains
Australia
Zone 9b