Hardy Australian Dendrobium Natives & their Hybrids
There are over 1500 naturally occuring Dendrobium
species and many more hybrids. Many Dendrobiums from
Hawaii and Southeast Asia are tropicals, yet many from the
Himalayas, Australia, Japan, and higher elevations of the
East Indies are perfectly suited for subtropical areas.
Of all the Dendrobiums, the hardiest - the ones that the
same plant can stand more extreme heat or more extreme
cold - are the hardy Australian Dendrobiums.
More than a dozen species are found ranging from
Tasmania in the South, through Victoria, New South Wales
on to the mountains of Queensland toward the North.
Some are found on rocky outcrops while others are from
the rainforest as well as many other environs one may find
on the east slope of the dividing range along the eastern
side of Australia. While much of Australia is totally dry
desert, the eastern slopes receive rainfall 6-8 times a month
throughout the year. While each species has found its
special spot along this 1500 mile stretch of sub-tropical
environment, most have proven themselves to be easily
adapted to every-day garden conditions in sub-tropical
regions throughout the world.
In California, Australian Dendrobiums are among the most
widely grown garden orchids and should certainly be first
choice for growers who require maximum temperature
tolerance. Most are known to survive temperatures as low
as the high teens and highs over 100F.
Peaking in winter and early spring, these plants are renown
for their great masses of pink, purple, white and yellow
along with their honey-like fragrance that fills the garden
This group thrives in temperatures ranging
from 32 to 90 degrees , but can take several degrees more in
either direction without suffering any damage. This makes them
ideal for outdoor culture in areas such as subtropical/coastal
and central California. People growing indoors should be able
to grow these dendrobiums so long as they allow night-time
winter temperatures to cool to the high 50's.
These orchids prefer bright filtered light such as might
be found under 55% percent shadecloth or a tree with foliage of
light to medium density. For those with light meters, 3000 to
4000 footcandles is a good level of light. Direct sunlight is fine
during the early morning or late afternoon since the angle of
the sun is low at these times; if sunlight is too intense you will
see scorching on the surface of the leaves. Without enough
light, plants may not bloom with as much profusion or color
Once a week during winter and a twice a week during
the summer is average for coastal areas, while the hot valleys
will need more frequent watering during the heat. Adjust
accordingly for cool, overcast days or hot, windy ones. A
general guide is to water thoroughly the day before the plant is
dry, judging by the weight of the pot or basket. Once a month,
it is a good idea to leach accumulated salts from your mix by
following up your normal watering with a second thorough
watering a couple hours later. For those growing on mounts,
increase watering to a few times a week during summer. Never
leave plants sitting in water; allow them to drain completely.
We recommend a balanced water-soluble fertilizer
such as DynaGro 7-9-5 at 1 teaspoon per gallon once a week
with your normal watering; for mounted orchids, use one half
If potting is necessary, use a well-draining mix such
as you might use for your Cymbidiums. We use a coconut with
perlite mix or a fine bark mix when we are potting new
divisions, but after they are established we typically do not pot them further up. Most of the Australian Dendrobiums can be let to crowd out of a pot, and simply be set in larger empty pots. Many make very attractive and huge, round hanging specimens, engulfing their original, small pot.