Nathaniel gave me a tall glass jar as a terrarium for my birthday last month. The available space inside the jar is around 10.5″ tall by 8″ wide. We went to the OrchidFest two weekends ago looking for small orchids that would do well in a terrarium. Based on my experience with another terrarium that I keep at work with a variety of plants, I knew that jewel orchids can handle the humidity and general terrarium conditions.
I ended up picking out two jewel orchids: Ludisia (Haemaria) discolor alba and a Goodyera rontabunensis. The Ludisia has bright green leaves with yellow veins and the Goodyera’s leaves are more of a forest green with white veins and pig-snout shaped white blooms.
I also selected a Platystele reflexa with tiny bright orange flowers and a Pteroceras semiteretifolia. The Pteroceras has a few new growths, but it’s hard to tell right now if they are flowers or new leaves. I picked these out from J & L Orchids who are based in Connecticut and frequently come to the orchid shows in the bay area.
All of the above orchids are surrounded by moss at the bottom of the jar. I wanted a slightly taller orchid to help balance out the selection. We ending up finding a stick-mounted Haraella odorata at Andy’s Orchids- actually it has three plants on the stick and one bloom that smells very lemony. We clipped the stick, which is really a skinny tree branch, so it would fit in the jar standing up.
When I got home from the OrchidFest, I was eager to assemble the terrarium. Nathaniel and I both did some research online and found a smattering of information here and there, but no real definitive source. We ended up trying the following to prepare the terrarium for the orchids:
1) Wash the jar with hot water and soap. Dry w/ paper towels.
2) Place an inch-thick layer of pebbles at the bottom of the jar. We used small aquarium style pebbles.
3) Add a thin layer of charcoal pieces on top of the pebbles. (helps to filter the water)
4) Finish with a layer of sphagnum moss and spray with water until damp.
Then I took most of the orchids out of their pots and removed any unattached moss. One orchid was in a tiny pot with bark and a little moss, so we left it in the pot and surrounded it with moss in the terrarium. I placed the mounted Haraella in the jar last and leaned it against the side of the jar. The terrarium is in our kitchen just to the left of the windows so that it gets some filtered sunlight but not too much. (Direct sun will heat the glass and increase the temperature inside the terrarium.)
Its been two weeks since I setup the terrarium. We’ve been taking the lid off the jar for several hours a day to allow some air circulation. All of the plants are doing pretty well so far. In the first few days, I think I made the mistake of letting water drip from a developing bud on the Haraella, because the bud fell off. 
Here are some photos of the individual orchids before I put them in the terrarium and then the assembled terrarium. I’ll keep you posted on how all the plants perform!
Overall, the plants in this terrarium are healthy and growing. I did lose the Pteroceras semiteretifolia several months ago. The leaves just shriveled and died pretty rapidly. The Haraella odorata was budding in the terrarium, but I think the humidity was too much for it because the buds kept dropping off. So, I took the Haraella out and hung it with the rest of our orchids (on shelving with lights) and there’s a bud about to open now. In hindsight, I think I tried to put too many orchids in the jar for the amount of space. The two jewel orchids inside it like to get kind of rangy and take up space. I feel like placing orchids in terrariums is a bit of a gamble because there’s not much information available about which ones will thrive in that environment. So far, the jewel orchids seem the happiest.