Orchids in hanging terrariums

Terrariums are in. Especially tiny, trendy, crafty terrariums fashioned out of everything from spice jars to light bulbs. Hanging glass terrariums are also popular and, I'll admit, are great for folks with windows but not a lot of windowsill. The problem is that, while many of these projects score points for aesthetics, they're horticultural disasters unlikely to last for more than a few months.

Take, for example this carnivorous plant terrarium:

  
It's visually appealing. It's self-contained. It's full of interesting plants. It's also doomed. First of all, it combines plants with very different cultural requirements. Nepenthes (the pitcher plant) are tropical plants that grow throughout the year, while Dionaea (the Venus flytrap) is a temperate plant, native to North Carolina, that requires a cold winter dormancy. Second, Nepenthes generally prefer a more open medium, like sphagnum moss and perlite, and a dense, peat-based medium like the one here will likely lead to rot. Third, Nepenthes are vines. Big vines. If it remains healthy, it will quickly outgrow the terrarium. And I'm just getting started...

There are, however, many other plants that do well in terrarium. Tillandsia (the ubiquitous "air plant"), for example. But also miniature orchids, particularly those of the subtribe Pleurothallidinae. Many prefer high humidity and constant moisture at the roots, making them difficult for anyone who doesn't have the space for a proper orchidarium. Fortunately, they grow well in hanging glass globes. I don't know how or when the trend started, but an increasing number of orchid growers have adopted this method to grow the odd Pleurothallid or two.

I have two Pleuros in hanging glass globes, a Pleurothallis alata and a Lepanthes calodictyon. The latter is a gorgeous miniature orchid, with densely patterned, ruffle-edged leaves and tiny red flowers that resemble insects. Mine came mounted on a small piece of cork. I placed moist sphagnum moss in the bottom of the globe and nestled the mount on top. Within a few months, various mosses began to grow, creating a nice green bed beneath the orchid. I keep the moss moist and mist the globe (one spritz does a good job thoroughly wetting the interior) once every day or so. The globe hangs about two feet from the window, so it receives no direct sun. Here's how it looks:

And here's a close-up of the flower:

While this is easier than attempting to grow Lepanthes calodictyon on a windowsill next to some grocery-store Phalaenopsis, there are a few things to keep in mind: it should never dry out, but excess water will promote fungus and rot, so water carefully; most Pleuros are sensitive to dissolved salts, so use distilled or RO water and fertilize weakly throughout the year; finally (this should be obvious), keep it out of direct sunlight to avoid cooking your plant. And above all, always research your plant's cultural needs, lest you end up crafting a beautiful disaster like the carnivorous plant terrarium above!