Well, I've taken the plunge and acquired a colony of hybrid Pterostylis
orchids. It should arrive within the next few days, so I am soliciting
advice on their culture. I have a fine book on cultivating Australian
orchids, but I am eager to know any hints or tips on how to get these
orchids to perform well in the Northern Hemisphere. I used to raise
Pter. nutans, but it is so long since I had them, I've forgotten
exactly how I grew them.

Any advice is welcome, at least in regards to the Pterostylis.

J. Del Col

Jadel wrote:
Well, I've taken the plunge and acquired a colony of hybrid Pterostylis
orchids. It should arrive within the next few days, so I am soliciting
advice on their culture. I have a fine book on cultivating Australian
orchids, but I am eager to know any hints or tips on how to get these
orchids to perform well in the Northern Hemisphere. I used to raise
Pter. nutans, but it is so long since I had them, I've forgotten
exactly how I grew them.

Any advice is welcome, at least in regards to the Pterostylis.


J. Del Col

Colony forming Pterostylis are usually the easiest of the Australian
temperate terrestrials to grow. Most of the hybrids available have been
bred with ease of culture in mind so they tend to be very forgiving. I
found the best approach to growing any temperate terrestrial orchid was
to stop thinking about them as an orchid and learn their requirements
from scratch. Culturally they have more in common with perenial bulbs
like tulips and hyacinths than Catts and Phal's.

They're mild temperate plants. I don't know where you live or grow your
orchids but they do require definite hot/cool seasons for best growth.
Check out the following website for suitable temperature range info:
http://www.bom.gov.au/climate/forms/...imagemap.shtml
If you stick to the capital cities with latitudes lower than about
mid-New South Wales for the most suitable climates. My plants
experience temperatures down to 0oC on winter nights.

It might be worth posting your question to the Terrestrial Orchid
Forum. There's quite a few non-Australians over there having success
with Australian terrestrials. You might want to see how they're doing
it.
http://terrorchid.proboards27.com/

Here's a rundown of what works for me:
About 50% shade is suitable. Too little light and the leaves start to
point upwards, too much light may cause the emerging leaves to burn and
in spring the plant may go dormant early.

Watering is something you'll have to learn to judge for yourself. Water
so that the mix is damp but not wet for any prolonged period during the
growing period. As the plants go dormant hold back on the water. In
Summer the pots should be kept dry, with a very light watering on very
hot days to stop the tubers dehydrating. By very light I mean that the
water shouldn't penetrate more than a few mm into the mix. If the
temperature is above ~30oC, moisture around the tubers can cause them
to rot. Begin watering carefully in autumn/fall or when the new shoots
emerge which ever is earlier. Start watering normally when the danger
of hot days is over. They don't need a particularly humid environment.

There are various mixes that are suitable. The mix needs to be free
draining but maintain sufficient moisture to stay damp/moist. Including
a bit of organic matter is usually recommended. You can probably get
away with a commercial potting mix mixed with sand or perlite and maybe
a bit of leaf mould (something fibrous so it doesn't compact too much).
I deflask pterostylis into a 50% perlite:50% potting mix (recommended
by Melbourne Zoo) but I can't comment on how they'll go in this mix
long term. Nesbitts Orchids recommends 45% loam, 50% course sand and 5%
peat moss + a small amount of blood'n'bone in their culture notes.
Last I heard Les Nesbitt had moved on from using this mix but it's
still suitable for Pterostylis and other Australian genera.

The mix I use is designed as a general Australian terrestrial mix so
it's probably more complicated than you need for your Pterostylis
hybrids. Unless you want to grow and have access to the more finicky
species, eg Diuris, Thelymitra, Caladenia etc, I don't know whether it
will be worth your effort sourcing the appropriate material for the
sake one pot of Pterostylis. FYI the mix I use is the one recommended
by ANOS Victoria: 2 parts ~2 - 5mm sand, 1 part loam, 1 part eucalypt
leaf mould, 1 part wood shavings/eucamulch + a small mount of
blood'n'bone. Whatever the mix a top dressing (~5-10mm) of casuarina
leaves, pine needles or small pebbles (eg the above sand or 7mm
pebbles) is recommended to lift the leaves off the mix to avoid them
rotting.

Regular fertilising is usually not necessary, especially where the mix
includes blood'n'bone and/or organic matter. Some growers have uses
weak applications with success.

Pests: Snails, slugs and caterpillars are the main ones. Aphids can
attack the flower stem. Fungus gnats like the mix but I haven't
determined how much of a problem they are. I usually don't have a
problem with anything else. Viruses are occassionally a problem in
Asutralia but I don't know whether the viruses that attack Pterostylis
are the same as those that infect the average cultivated exotic.

I hope I haven't made you want to get a refund on your plants. My
cultural conditions are biased by the fact that I grow number of
Australian terrestrials and I need to have conditions set up to suit
both easy and harder species. Invariably there will be people who grow
a pot of Ptst. curta amongst their epiphytes and will tell you to grow
your greenhoods in cheap potting mix next to your Cymbidiums and forget
about them. By all means take their advice. If your plants can take the
abuse and still grow, flower and multiply it's usually less work to
give it to them.

Andrew

Thanks very much. Your info should prove very helpful.


J. Del Col

I forgot to mention that I live in Philippi, West Virginia, USDA Zone
6, (more or less).

The plants in question are coming from Washington state.

J. Del Col

Jadel Wrote:
I forgot to mention that I live in Philippi, West Virginia, USDA Zone
6, (more or less).

The plants in question are coming from Washington state.

So long as you can provide the cool temperatures during the winter you
should be OK (aim at providing ~USDA zone 9-10 seasonal temperatures).
As I mentioned, Check out the Terrestrial Forum. There are a lot of
forum members from the colder parts of North America/Europe who grow
Pterostylis. They'd be better suited to telling you how to grow them
outside their normal climate range as opposed to someone slap bang in
the middle of where they live naturally.
Andrew

Andrew wrote:
Jadel Wrote:
I forgot to mention that I live in Philippi, West Virginia, USDA Zone
6, (more or less).

The plants in question are coming from Washington state.

So long as you can provide the cool temperatures during the winter you
should be OK (aim at providing ~USDA zone 9-10 seasonal temperatures).
As I mentioned, Check out the Terrestrial Forum. ...


I have and am now registered with it. Thanks for providing the link.

J. Dle Col