Hi Silver77,

You may want to post this question over on the Orchid Forum.

The type of orchid will depend on the size of the unit. Will you plant the orchids in the unit or keep them in their individual pots? Also, how bright will the lights be? Phals don't require the same amount of light as for catts.

For air circulation, you can try a small computer fan or a large enough aquarium air pump.

Penelope

How big is your orchid terrarium? You need a pretty tall one for most standard 'chids. Phals. are suitable for terrs, but I have found that mine aren't blooming, even though the leaves are nice and purple (sign of plenty of light). I think they really do require that cold period for blooming, so I wouldn't recommend them for terrs. Go for minis. They tend to like to stay moist and don't require a lot of air circulation. And like Penelope said, it does depend on whether you want them to be permanent in your terrarium or just keep them in their pots and use it as a small greenhouse. For mini orchids, check out Andy's Orchids. He has lots, and the best thing is that they're species, so they are actually easier than a lot of hybrids, IME. My C. pulchellum in my terr is the only orchid that is almost always blooming. I love it! Most other bulbo's and Cirrhopetalums will be good for terrs as well.

Check out Oak Hill as well. Their selection rivals andy's and the plants are bigger and MUCH cheaper.

Without air flow your chances of growing orchids in a terrarium decrease greatly and vastly limit the types you can grow. Without air flow, carnivores, bromeliads/tillandsias, ferns, mosses, and a million other plants will do better then most orchids. However, add a small fan and some good lights and the sky is the limit!

IMO, Oakhill is a very good choice for inexpensive species. However, I do find their species list to be of more 'common' types and rather limited on the mini's. Andy's is definitely much more expensive, but I do like his selection of offerings better [he seems to have more mini's available and w/ my limited growing space I have to avoid the large plants].

As alreay mentioned, so much depends on the terr size you're thinking of and what all you plan on providing light-wise, etc. Catts tend to require lots of light to bloom.

I have several mini-catt hybrid seedlings that are putting on some good size now in my 60 gallon terrarium (no fan, but some good vents along the front and sides). I have three 40 watt compact fluorescents over the tank, and they are keeping a nice light green color, so I think they are getting enough light (plus, they are about 4-5 x their original size).

No blooms yet, but I don't expect any possibility of blooms for another year or so, given their age. So, it can be done: raising minicatts in a terrarium, but I think the advice here is sound. I'll try to post some pics later.

Small, hot growing Dendrobiums are another good candidate. Unfortunately, my first Dendrobium in the terrarium, 'Emma White', has started to get a little big for the terrarium (even though the terrarium is 24" tall). It blooms like clockwork, every 6 months, and puts out a newer, bigger cane in the interim. When it's in bloom, though, it is always my favorite.

Hmmmmmm. . . re-reading this thread, I noticed something I must have skipped over before. Silver, you say that you cut out a black spot on your cattleya. Not all spots and marks on orchids are rot. If they feel firm to the touch, just leave them. It's quite normal, kind of like freckles. You know it's rot if it's mushy and starts to spread. Cutting out a spot that's not causing any trouble might actually start some trouble, because you are openning up a wound in the plant that a fungal or bacterial disease can now enter. Don't worry about it too much; it's too late now, and I did the same kind of thing when I got my first orchids!

Homer: I recently got Emma White, and was wondering how on earth she fit in your terrarium! =) The current blooming cane is about 2.5' tall, and from the looks of things, it's only the fourth or fifth cane! My Dend. NOID was also getting too big for my terr, so I took it out. And all this time I thought it was a mini and would stay short. . . guess i was wrong!

My moth orchid is doing pretty well. It's tiny but growing. I'd like to get a lady slipper. My research indicates that the type called paphiopedilum, and in particular the paphs with mottled leaves, like warmth, humidity, low light. My long 40 watt flourescent tubes are low light compared to natural light. Cats need night-day temperature difference of at least 10 degrees to bloom. If your lights are very bright you might have that, and enough light too. (I got a cheep timer for my light--$5)

I'm finding that only some Paphs. do well in terrariums. They don't actually require very high humidity (50-60% is good enough for them), and the last bud on my Maudae hybrid actually rotted before blooming, because the humidity was very high, with little air circulation. My Paph. Dellaina has not bloomed yet, so i'm wondering if it's one of those that needs a basic mix (high pH). It's currently planted direclty in the substrate, which is cedar bark mulch (low pH). so I'd say Paphs are a good choice, but they aren't as great in terrariums as bulbo's.

Are the aspasias good for terrariums??

I'd never heard of aspasias, so I looked them up, and yes, it appears they would be good for terrariums, as long as the terrarium was tall enough and had a fan or two.