The English pop-rock group The Hollies, who once sang, "All I need is the air that I breathe," could have been referring to air plants. There are more than 650 types of air plants (Tillandsia spp.) that can grow -- and thrive -- without soil.
Why are air plants so easy to grow? These bromeliads get all of the water and nutrients they need through their specialized leaves. Air plants use their roots only for attaching themselves to rocks, trees, shrubs, and the ground. Native to the southern United States, Mexico, Central America, and South America, air plants are warm-weather lovers that can thrive on neglect.
Many grow with strap-shape or slender triangle-shape leaves, and most have attractive tubular or funnel-shape flowers.
Even though they are easy to care for, there are a few rules to follow when growing air plants:
- Constant air circulation -- as the name indicates -- is paramount to keeping your plant happy.
- Air plants need some moisture; from late spring to mid-autumn, mist daily. In winter, mist only once or twice a week.
- Fertilize monthly in spring and summer using a low-nitrogen liquid fertilizer mixed at only one-quarter strength. In general, fertilize weakly.
- Although they love warm weather, most air plants need protection from full sun. If it's a type that grows naturally wild on trees, keep it in moist, partial shade. If it is a ground type, such as T. cyanea or T. lindenii, grow it indoors in bright, filtered light and outdoors in partial or dappled shade.
- Don't let an air plant sit somewhere that's colder than 45 degrees; it will die at those temperatures. If you live in Zone 9 or warmer, you can grow an air plant outdoors all year if you keep it dry during the winter.
Air plants look great alone as architectural elements. Place varieties such as Tillandsia aeranthos 'Amethyst', also called the rosy air plant, into a pot or against a container that will complement or contrast with its pink flower spike.
Play off the spikiness of the foliage by grouping three Tillandsia ionantha and add a tiny toucan, parasol, or other tropical touch.
Air plants that are naturally suited to growing in trees can be lashed against a protected wooden post using translucent fishing monofilament and a bit of sphagnum moss to add extra moisture. Tillandsia species also make fine companions on a planted branch with orchids since they like essentially the same conditions.