Air plants, genus Tillandsia, are the most portable citizens of the plant kingdom. As a type of epiphyte, air plants have no roots, require no soil and grow on the branches of larger trees non-parasitically. Native mostly to Central America, some prefer dry desert climates, while others thrive in warm moist jungles. They get all their nutrition from the dust and moisture found in the air.
Air plants are composed of many long, pointed bracts1 or more simply, they look like rosettes, a little bit like an aloe plant. Air plants are usually around four to six inches (10 to 15cm) tall, though some extreme species can grow up to two feet (0.6m). Desert and mountain air plants are usually grey with scaly plates called trichomes covering their bracts. They also have thin roots used solely to anchor them to the rocks or trees that they live on. Jungle air plants tend to be green, though some take on a reddish or purplish hue, and some are green with reddish tips. They tend to resemble punk hairdos, and look remarkably natural perched on top of paper cups with faces drawn on the sides.
Air plants have a relatively simple lifecycle. When happy, they grow larger. At some point, the plant will bloom. A month or so after the flower grows, the plant will produce 'pups', little miniature air plants that grow out of their side. When the pups are almost as large as their parent, they can be detached; if you have to tug and rip, they're not ready yet. The parent plant can produce several 'litters' before dying.
Air Plant Care
Air plants thrive in warmth, lots of indirect sunlight, and humidity.
Air plants do not like the cold, and will be unhappy in an environment cooler than 10°C (50°F). At the other extreme, they start feeling baked when it's over 32°C (90°F).
Air plants don't mind basking in the sun, but they prefer to keep out of strong direct sunlight. Where you raise your plant will vary depending on your location and environment. Air plants being raised in lower latitudes should be kept out of the strong direct light of early afternoon; sun filtered through porch screens and lightly fogged windows suits them just fine. Those raised further from the equator won't mind the weaker sunlight. If the sun is particularly weak, consider using a fluorescent plant light. Desert plants prefer their light somewhat stronger than jungle plants, so it pays to find out where your plant hails from.
Plants that get too much light will develop brown patches of sunburn. Plants that get too little light will lose their colour and start looking straggly.
Air plants get their nutrition from moisture, so it's important to wet them properly. A thorough daily misting will keep your air plant happy and chipper; alternatively, give your air plant a five-minute dip in a cup of water around three times a week. If your locale is very dry, it's best to use a combination of bathing and misting. After wetting your air plant, don't leave it anywhere cool or humid; if your air plant doesn't dry off after four hours it could begin to rot. Take particular care that the base is dry before returning it to its perch.
If your plant is well watered it will feel stiff and full. If it's dry its leaves will curl up and feel softer and its colour will fade. Try not to soak the flower when it blooms, as it will rot more easily than the rest of the plant. You can cut off the stem when the flower dies.
While an air plant will manage fine as long as you provide these conditions, air plants, like all living things, have their preferences and don't mind being coddled. They prefer being misted with rainwater over tap water, and indoor plants will appreciate being fed with a weak solution of low nitrogen fertiliser during the spring and summer.
Because air plants have no roots, they are generally not potted. Some feel that having a rootless air plant rocking on the windowsill is inexcusably strange, dangerously vulnerable or aesthetically unpleasing. If you are one of these, fear not. There are several ways to attach your plant to another object.
Air plants look great mounted on rocks, seashells, mirrors and driftwood. If you're mounting on driftwood, soak out the salt before attaching the plant. Be careful that whatever surface you choose is not one that will be damaged by dampness, or one where water will pool or be absorbed.
You can use almost any sort of glue to mount them; keep in mind that it should be clear and waterproof. You can also mount your air plant with wire or staples, but don't use copper wire and don't staple the bracts or any central part of the plant.
The nice thing about air plants is that they're not picky about direction. Sideways, backwards, upside-down - it's all the same to them. If you grow your air plant on a string dangling from the ceiling it will eventually grow into a prickly ball.
Your air plant's bracts will dry up and die naturally after a while, but you can slow the process by moistening the tips daily. When they're dead you can tug them off without any trouble.