Recently someone in our garden club asked about how you put together a terrarium. Since our house cleaner also recently knocked over and broke the small terrarium we had (sitting on an overly-tippy end table), I took that opportunity to pick up what I’d really wanted all along — a taller, free-standing terrarium, big enough to house full-size orchids (24″ high interior).
A trip to Trader Joe’s for cheap orchids, and some potting soil, little plants, pebbles, and moss from the garden store, and I was ready to go. There’s very little to instruct, really, but here goes, in case it’s helpful:
a) I started with a layer of pebbles in the bottom for drainage, followed by a layer of soil.
b) I added the orchids next, and this bit, I’m not sure I did right, but since I know orchids prefer their roots to stay mostly dry, I left them potted in their little plastic pots filled with orchid bark, and just nestled those in the soil.
c) Then I tucked in some little terrarium-type plants around them. Your nursery can advise you on what’s well suited to this, but just keep in mind that what you’re recreating is essentially a moist, jungly environment. Terrariums are related to Wardian cases, which were used to bring tropical plants back from the tropics to England, keeping them alive on the long voyage. So I wouldn’t use a terrarium for succulents!
d) I added a layer of moss, which serves the dual function of looking nice and also retaining moisture in the soil.
e) That’s it! Put the lid on, and you have a moist, mostly self-contained environment. It should need water rarely. My understanding is that usually terrarium plants want plenty of indirect light (not blasted with sun) — imagine that you’re under the tree cover of a tropical jungle. So I put mine by a window that’s near an overhanging porch roof.
Now, the next step is that eventually, these orchids will lose all their flowers (though it’ll take a few months; I try to pick orchids that are mostly buds, with just a few blooms, so the show is sure to last a long time). In theory, one can then take care of them appropriately so that they’ll come back, year after year. I haven’t actually done that yet, but I have friends that do it regularly, and swear it isn’t hard.
When these are done, I’m hoping to try that, and I’m also hoping to replace one of them with a more interesting variety, since they’re all, I think, pretty standard phalaeonopsis (or moth) orchids, and there are so many more cool varieties out there. I’m looking forward to eventually experimenting with other types.
Living in South Florida, my mom just hangs her orchids in a tree when the blooms finish. They bloom again every year.