Date: Mon, 20 Oct 1997 11:51:58 +0900
From: Greg Steenbeeke <gstee@dlwc.nsw.gov.au>
Subject: [16683] re: [16634] Dockrillia cucumerina

Hi David and OLD members

Another Q about a species I know intimately from a long term cultural
and exploratory history...

Distributed from the Burragorang (and Kowmung) Valley west of Sydney
to south-east queensland, this species is an epiphyte preferring the
UNDERSIDE of branches of Casuarina cunninghamiana (the river oak),
although it will also grow on the trunk at times, and can be seen
hanging in mid air off it's mount.. (right, Steve Kemp!) I have also
seen it growing on Backhousia myrtifolia (the Grey Myrtle).

Favoured locations: Narrower gullies and humid microclimates, often in
mountainous country, where it will grow above water. Wind movement is
constant, although not always more than "barely noticeable". Light
levels are low - moderate (more often low), to the extent that "in
situ" photographs of the species' habitat are disappointingly dark...

I have the species growing happily under 70% shadecloth receiving
water at least once a day. It is (or was) tied to a casuarina log, and
grows around the log which is now in a "trunk" position. The other
plant I have is on a slab of Banksia serrata bark, hanging at about 80
degrees (90 being vertical), and getting watered 2 or 3 times
daily. There are many plants around with it happily growing on cork. I
think hardwood palings will not suit the species as they are too
smooth, and it would appear to use the texture to it's advantage in
putting it's roots deep into the furrows and crevices.

In your conditions, I would put it in a shadier or darker spot under
the lighting, and would be wary of exposing it to high temperatures
(over 80F) for extended periods. It will withstand long periods of
cold weather, although freezing will kill it. It may be that It will
survive in the bathroom during winter. You wouldn't be the first to do
this (although Supreme Commanders, Household, often
complain!... Although it can get quite warm where it grows, it is in a
cool microclimate, and often in mountainous areas where temperatures
are also reduced.

Looking at your climate data (from the State Climate Office website),
it would suggest it will require protection from cold during Oct -
Apr, and will only need to be kept above freezing, not heated
greatly. In fact, I believe that like some other dockrillias
(esp. D. striolata), warmth in winter may restrict flowering.

For those who don't know, mountainous by Australian standards relates
to about 2000 - 4000 feet. We are, after all, the lowest, flattest,
driest continent (and the most most sparsely inhabited after
Antarctica!), and the term often relates to terrain rather than
altitude.

I have posted pictures at the ANOS site, with articles at:
http://www.ozemail.com.au/~graemebr/photos.html#Dockrillia.cucumerina
and photo at: http://www.ozemail.com.au/~graemebr/photos/dockcucu.jpg

You should visit tha ANOS site, as it is interesting and often
contains cultural info (mind you, that goes for everyone!)

One other thing: You will notice that many of the Australians are now
calling the rhizobium dendrobes by the name Dockrillia. It was
recently resurrected, and seems to have gained widespread support, as
surely the plants look nothing like softcanes. Personally, I agree
with it, as there are as many differences and similarities between the
sections of Dendrobium as there are between the various genera in
Sarcanthinae (eg Vanda, Aerides, Rhynchostylis, Phalaenopsis)...

Good luck with the species, and don't be surprised if it "keels over".




Date: Tue, 21 Oct 1997 11:48:33 +0200
From: "Wellinga, Simon" <Simon.Wellinga@nl.origin-it.com>
Subject: [16696] Re: Subject: [16634] Dendrobium cucumerinum

Dear David,

With respect to your request for cultural advice on Dendrobium
cucumerinum, the following. I have grown this species since 1981 and I
don't find it particular-ly temperamental in cultivation. I grow my
plants either mounted on Mexifern or grape vine, or just hanging on a
piece of nylon rope, under four 36 Watt TL-lamps in the 'dry' end of a
'vitrine' in the living room (such, after successfully having grown
the plants for some years in a window sill). Temperatures under these
circumstances range from 28-35 C during the day and 20-22 C at night
during summer, and 18-22 C during the day and 12-14 C at night during
winter.

Dendrobium cucumerinum indeed appears to be a cool grower, since most
growth activity is shown during the cooler months of the
year. However, even then development is rather slow, each rhizome
branch not making more than 4 to 5 new leaves per season (what you
consider to be pseudobulbs are in fact the plant's succulent
leaves!). Flowering occurs from the end of June till Sep-tember -
their perfume always reminds me of the teddy bears I had when I was a
boy!

What is essential in growing this species is, that the plants should
be kept rather dry. So, no daily misting as you were told, but (given
the temperatures mentioned above) watering once per 5-7 days during
summer, and once per 8-10 days during winter. As applies to plants
grown on Mexifern, even under this watering regime care should be
taken not to moisten the Mexifern slab, since this will surely result
in a complete loss of the roots. Watering in this respect means
watering the plant and its roots, without wettening (or, worse,
soaking) the slab (in case of cork slabs this might be less
devastating). Fertilizer (in the normal 'half dose' orchid strength)
can be applied once every 3 to 4 weeks. Cultivating the plants this
way may seem a bit callous - especially with plants mounted on cork
slabs or plants grown without any support- but it is my experience
that when the watering frequency is increased plants grow much less
well and form less and smaller leaves, even when the root system
remains intact. However, this recipe applies to plants grown in a
'vitrine' in a Dutch living room, which means temperate to cool
conditions during winter and temperate to warm conditions during
summer, with fairly high relative humidity throughout the year (this
except during long spells of frost in winter, when air humidity drops
significantly). Atlanta though sounds like awfully hot summers to me
and therefore (especially if your plants are grown in the open during
the summer) you might need to water a little bit more often. Still, I
wouldn't recommend moistening the slabs on which the plants are
mounted.

Thus, cultivation is quit easy. My plants have never suffered from any
pests, this with the exception of a vine weevil that managed to find its
way into the 'vitrine' and feasted on a few newly emerging leaves
(damage that remains visible for years). The only problem that I have
encountered so far is a more than occasional and progressive 'shedding'
of leaves just somewhere in the middle of a rhizome. This happening,
close inspection reveals that part of the rhizome has turned brown and
dead. My remedy is to cut out the dead parts with a sterilized pair of
scissors or a knife and to withold watering for a few days till the
fresh wounds have dried in. Yet, if you're lucky this story has a happy
ending: you will have one plant more!

Best regards and happy growing,

Simon M. Wellinga
Heerenveen, The Netherlands
E-mail: Simon.Wellinga@nl.origin-it.com