Brassia is a genus of orchids in the Eastern hemisphere commonly called the “spider orchid” due to the long, bizarre shapes of its sepals, which spread out like a spider’s legs. The spider orchid’s scientific name, Brassia, comes from William Brass, the botanist who helped originally collect it. Spider orchids are found in rainforest-like conditions as far north as Mexico and as far south as South America, though like so many other beautiful tropical orchids they’re most commonly found in the Andes Mountains of Peru.
Given their natural habitats, these orchids prefer conditions with extreme humidity and lots of warmth to help them flourish. They can be identified not only be their spreading habit but by their bright colors, as Brassia plants can grow in spotted, bright orange, red, and many other vivid shades. They’re epiphytes, and though they mostly are limited to the rainforest the most far-spreading is B. caudata, which is the only species found as far north as Florida. One interesting characteristic of the Brassia genus is how its plants are pollinated.
They attract a specific breed of wasp, which mistakes the plant for an insect and stings it. This sticks the wasp to the plant, and when it travels to a new Brassia plant it manages to pollinate them. So if you try to grow these plants yourself, don’t bother trying to pollinate them, unless you can put up with spider-hunter wasps in your shade house!
- Light: The rainforests of the Andes have heavy cover from the forest canopy and so their plants tend to require only partial sunlight. Too much direct sunlight will cause leaf tip burn.
- Water: Mist them every day and never allow them to dry out. They need extremely humid conditions to thrive.
- Temperature: Warm tropical temperatures above fifty degrees. They are not tolerant of frost.
- Soil: As epiphytes, they don’t necessarily need a medium at all…they’ll do just fine hanging, or mounted on a vertical surface. But they can also be grown in hanging baskets, in which case they’ll need a well-draining medium like chopped sphagnum.
- Fertilizer: Feed regularly with a balanced, diluted fertilizer like a 20-20-20 and up their feeding if the Brassia’s blooms are insufficient.
They can be propagated by dividing their pseudobulbs, at the base of the plant, and repotting them in warm, moist conditions. Using a sterilized tool will reduce the plant’s chances of infection. Many gardeners bag up their new cuttings to seal in moisture, which is especially effective in plants like this that require lots of ambient water to grow.
Repotting epiphytes is almost contradictory; however, if you do grow these in a basket then it’s not a bad idea to switch out their medium every once in a while. Lift the plant and replace it, then backfill with soil. But spider plants grow best when hanging, so repotting really shouldn’t be an issue. Don’t get mad at yourself if you can’t get these plants to propagation; orchid propagation is far from simple and even experienced gardeners struggle with it sometimes.
The tailed Brassia, or B. caudata, is probably the single most prominent member of the genus, both because of its distinctive spots and its wide distribution. A spider orchid that especially displays the long sepals characteristic to the genus is the arching Brassia, or B. arcuigera, which can grow in bright yellow or orange and as a result develop a quite striking appearance. The type species, however, is B. maculata.
Mimicking the tropical conditions in which they grow isn’t easy, but it’s what you’ll need to do if you want to grow spider orchids. If they aren’t given significant amounts of moisture every day and kept in a shaded, warm environment, they simply will not grow. Remember also to keep them well-aerated… a fresh breeze will do wonders. These are obscure, fairly rare plants that are only found in specialty sources or the wild, so it’ll be difficult to grow them, but that’s no reason that—provided you can mimic tropical conditions—they wouldn’t make good domestic specimens.