Australian Native Dendrobium and Sarcochilus
The Australian native orchids mostly grown by orchid growers
are Dendrobium and to a lesser degreeSarcochilus.
Firstly don't let the big names put you off, Dendrobiums are pronounced
Den dro bee ums and Sarcochilus Sar co chil us.
Now that we have got that out of the way we can carry on, now you know
what you are reading about.
Dendrobiums have canes or stalks varying from short, about 10cm tall to
longer up to about, usually 40-50cm, but in the case of one Dendrobium
species 100cm,and one of the Queensland Dendrobiums can grow up to 200cm
or more. ( It would be doubtful if you would find one this big in cultivation)
They vary in thickness from about 5mm diameter up to 4 or 5 cm diameter
as in the case of the larger
They grow easily in our backyards in Perth with some protection from our
fierce summer sun. They do not flower if kept in full shade, but relish
about 50% sunshine in summer, ie under a tree with mottled light or in
a shadehouse with 50% shade-cloth. If you grow ferns in a shade house
and they are growing well, then yourAustralian native orchids will not
flower very well if at all as it will be too shaded,they need more sunshine
than ferns. In winter they do well if put out in full sun and watered,
only if we have a long dry spell, a week or two without water in winter
will not worry them, in fact I find it beneficial.
I do not water mine at all once I have put them in full sun after the
last of the 30 degree days are finished.
In autumn and winter I leave it to the rain to do the
watering, except if we have not had rain for two to three weeks. In summer,
owing to the very porous mixture, they should be watered every day or
every 2 days.
They are not fussy about fertiliser, liquid fertilisers are OK as is slow
release or even Dynamic Lifter and sheep manure. If you use slow release
try to use it so that fertiliser is finished 2 to 3 months before flowering
is due. Very probably you would have bought your Aussie Native in flower
so it will flower again next year at this time all things being equal
and correct. If you use liquid fertiliser try to use a balanced fertiliser
in preference to a high nitrogen. If you use Dynamic Lifter or sheep manure
it will cause the bark mixture to rot quicker and you will have to repot
sooner than if you use liquid or slow
The potting mix used for these orchids is usually exclusively
pine bark graded to a size to suit the plant and you may find some blue
metal stones mixed with the bark. The blue metal is thought by growers
to help dry the mix after watering. As these plants originally grew on
trees as, what is called "Epiphytes" (not parasites) their roots
dry out fairly quickly after rain. When Dendrobiums and Sarcochilus are
watered in pots in pine bark the water can quickly drain away and allow
the roots to dry out some.
Repotting should ideally be carried out when the plant
has finished flowering, but please remember theseplants do not need large
pots until they become large plants.
A plant growing well and about 10 years old could still be growing in
a 10 or 15cm pot and still not need repotting.
The bark should be clean and not have any soil mixed with
it or it will stay wet and
cause the roots to rot, causing the plant to wilt and the canes to shrivel
as if it has not been watered (The rotten roots cannot supply the plant
with moisture). The best bark can be obtained from a specialist Orchid
nursery such as Ezy Grow and is labeled Aussie Bark or Debco bark.
If you are worried about repotting or any other problems
the Wanneroo Orchid Society hold a workshop every
year, usually the first Sunday in October.
At the workshop you can have your plant repotted by an expert and be shown
how it should be done.