All About Air Plants
Air plants are an interesting curiousity: they don’t require soil to grow. Often people think this means you can just shove them on a shelf like a tchatchke and never care for them again, but like other plants they do still need light and moisture. Here’s the low-down.
What are they?
Air plants are in a plant family called bromeliads, tropical plants that often store water in tightly-cupped leaf structures. (The bromeliads also include pineapples, probably the most familiar example of the family.) The air plants are a genus called Tillandsia.
Tillandsia are epiphytes, meaning that they grow upon another plant rather than in the soil — in the crook of a tree branch, or even in a crack in rock. Other common examples of epiphytes include many orchids and mosses as well as Christmas cactus (Schlumbergera cvv.). Actually, the most common Tillandsia is something you will easily recognize, though you may not have known it was related to the more exotic air plant specimens: Tillandsia usneoides or Spanish moss, which grows draping from tree branches throughout the American South.
Because these plants don’t depend on soil, they get all the moisture and nutrients they need from the air (hence, “air plants”). Moisture comes from rain and humidity, whereas nutrients come from decaying plant detritus, insects, and so on. This is all absorbed through the leaves. Air plants often do have roots, but their only function is to anchor the plant in place.
There are many different kinds of air plants, though most have the familiar “spiky” shape. Some grow in large clusters of plants. They will flower, with unusual papery blooms in a rainbow of colors in the pinks, purples, blues, reds, and yellows, often very long-lasting.
Air Plant Care
Light and Water
Air plants want bright light, but full sun may dry them quickly. Bright indirect light or filtered sun is best.
They will do best in a humid environment: in the bathroom or the kitchen are often the best places in the house for them.
How much they need to be watered depends on the humidity level. Let the plant dry thoroughly from the last watering before watering again. In a nice humid spot, once a week may be sufficient, but in a very dry environment, 2–4 times a week will be healthier. You can water by thoroughly misting from all directions, or by simply immersing the plant in water briefly and shaking the excess off. Use room-temperature water.
The leaves of your air plant should generally be supple and velvety. If they are crisp or curled, the plant is not getting enough moisture and you should increase its watering.
Air plants don’t need a lot of nutrients, and over-fertilization is very bad for them. However, they do need some fertilization over time to continue to grow and thrive. I recommend an organic liquid fertilizer such as fish emulsion, at half strength. Apply it monthly during the spring, summer, and fall with a liberal spray onto the foliage.
Because air plants don’t need soil, there are many options for what you do with them. You can use them “loose”, tucked into a crevice in just about anything, or you can mount them with wire or glue. You can make a really natural environment by mounting them on driftwood, branches, or rocks, display them in the openings of glass terrarium containers, or stuff them into giant seashells like some kind of squid-plant monster.