Thanks for sharing that link! I've posted the following in other threads but figure I'll add them to this one as well...

Miltonia flavescens in snow

Vanda coerulea in snow...

http://farm5.static.flickr.com/4007/...8a137a3e_m.jpg

Also, here's a good discussion on the cold tolerance of Epidendrum conopseum.

Hi,
I'm new here & have found this a very interesting topic. I'm in Australia, Newcastle that's about 200kms north of Manly in Sydney and just a bit warmer through the winter months, but not much. I'm not that far off 60 y.o. and never recall it ever going below around 5degC overnight min. & we don't get frosts. I have a very small garden with no room for an orchid house of any kind but I do have a number of Plumeria ( frangipani ) trees and native palms. I grow what orchids I have either in pots through the garden or mounted on these trees. My main problems in this situation are snails, grasshoppers & caterpillars. As far as climate goes, I grow on the trees Oncidiums, soft cane Dendrobiums, non-phalanthe Aust. native Dendrobiums, Slc / Sc / Blc etc ( I think hybrid vigour is important here ), Laelia anceps, Miltonia spectabilis & X bluntii & a Trudelia(Vanda) cristata X. They get what shade and shelter the trees provide in the summer, that's pretty much bright shade & those on the Plumeria get pretty much full sun in the winter. They get what ever the weather throws at them. This includes some extreme heat & both hot & cold dry winds. I do what I can with a hose but they are pretty tough and seem to get tougher as time passes.
Again I was really interested in this topic & have taken a lot from it...have a new list to search for...ho, ho, ho.
A question..I have a Mystacidium capense, a little African monopodial, I wat to put it onto one of the Plumerias but it seems it likes lower light levels from my investigations. However, it's habitat description doesn't sound that it would in habitat...Acacia scrubland! Has anyone grown it in bright light with success?
Ron

ronkbrown, thanks for sharing!

Mystacidium capense is one of my favorites. Mine is growing in Cattleya light and it does great.

Here's a list that I compiled of Monopodial Orchids Outdoors in Southern California. You should be able to grow most, if not all, in your climate.

It would be great to see photos of your orchids mounted on your Plumerias. Here's a group on flickr dedicated to growing orchids on trees.

Was typing a reply & it disappeared? wonder if it got through?

Obviously not. Here we go again. Thanks for the replies. My computer skill isn't up to pics 'yet' but when/if I get there I'll certainly have a go. I'm barely managing to navigate this web site at this stage & mostly finding where I want to be by accident...LOL
Thanks again for the very handy hints...Ron

@ undergrounder
"From your tester list, the falcorostrum might need a little bit too much cool humidity to survive a dry temperate summer as a true epiphyte."
There used to be a magnificent clump approx 60 cm across of D. falcoroustrum growing in a chinese elm ulmus parvifolia in Hyde Park in Sydney. I can't get mine (potted) to flower reliably in Sydney, but it used to flower its head off in Melbourne... maybe needs a bit more winter chill?

Very interesting topic epiphyte.
Can you specify for how many days or hours could maintains the minimum temperature without problems?

On florence the temperature have a range between:
-2°C : during some night on winter.
But when this happen during the daytime the temperature remain at 0 or 1 °C.
and
36°C : some days during the summer

However i read that for avoid to freeze the soil of plants grown in pots could be useful put an non-woven fabric.

alessandro, that's an excellent question. I have no idea. Here's what I recently posted in another forum though...

**************

"The ability to reduce the freezing point of water that's inside the tissues of that plant and also, once that water freezes, to allow that plant to survive freezing temperatures [helps]," Dr. Francko said. "It can be frozen solid and still be viable."

We all know that cold and dry is a better combination than cold and wet...but why is this the case? For a while I kind of figured that it had to do with reducing an orchid's susceptibility to rot. This could certainly be true...but in terms of freeze damage...an orchid that's been dry over a certain amount of time...or "dehydrated"...will have less water in its cells. With less water in its cells the less damage it might sustain during freezing.

Practically speaking, while it might be a challenge to keep a mounted orchid hydrated during summer...that same challenge might work to its advantage during winter.

I've been meaning to conduct a simple experiment to see how well this works out. Basically, I would take two leaves from the common Jade Plant (Crassula ovata)...a freshly separated leaf and a leaf that had been removed a week earlier...and put them in the freezer. Not sure how long I'd leave them in the freezer though. Then I'd compare the extent of the cold damage in both leaves.

What do the Jade Plant and many orchids have in common? Crassulacean Acid Metabolism (CAM). It's basically a technique that plants from arid climates use to reduce water loss during the day. As the name implies...this method of metabolism was first observed in the Crassula family. A side effect of CAM is succulence.

While most orchids do not occur in arid climates...many of the epiphytic ones can be considered to occur in arid microclimates. In fact, the percentage of CAM orchids occurring in a given section of forest is a good indicator of where that forest falls on the moisture continuum.

A fun tidbit for your friends that are really into cactus/succulents is that the Orchidaceae has more CAM species than any other plant family...including the Cactaceae.

All things being equal...in terms of cold damage, I'm definitely leaning towards a CAM orchid being safer mounted on a branch without any moss than in a pot.

**************

What I recommend is making a list of all the subtropical and tropical plants that grow outside in your area. Look up the distribution of each of those plants. Chances are pretty good that some epiphytic orchids share the same distribution ranges. It doesn't guarantee that those orchids will be as cold tolerant...but it is some supporting evidence.

You should also contact my friend Tomas in Rome, Italy. He's been growing quite a few orchids outside year around for some time now. Here's how Florence compares to Rome...

http://chart.apis.google.com/chart?c...0|70|80|90|100
Sources: Orchid Culture, Weather Reports,Temperature Charts

Thanks for the explanation. :)
I have send a message at Tomas a few moment ago.

Note:
The problem with average temperature is that there are just average, given how quickly orchids react i prefer give the worst case scenario.

I found that list for orchid that can take the cold (27 - 100F):
Cold Hardy Cattleyas
Sarcochilus

epiphyte78
What do you think too add at each orchid on your list even if has a nice sweet strong scent?