You don't have to have a green thumb to grow air plants. They survive mostly on air and an occasional watering.
"Air plants are in the Bromeliad family," said University of Tennessee Extension agent Tom Stebbins. "Tillandsia is the Latin name for the genus of hundreds of species found in Central and South America and Mexico and the southern United States."
The plants absorb nutrients, especially calcium and water, from the air and rainfall, Stebbins said. "They use foliar minerals (calcium, magnesium, potassium and phosphorus) leached from the plants. This provides an abundant supply of nutrients to the plant rather than through their roots."
Some dangle from trees, such as Spanish moss, an air plant often seen hanging from live oak trees in the southern United States.
One plant will grow to maturity, then flower. From this mother plant, one to eight offshoots, or "pups," will grow out on stems.
Most air plants will die if planted in soil. It is best to just attach or glue them to cork, coral, stone or driftwood, experts say. They can be placed in glass globes as well.
They are commonly sold as low-maintenance houseplants. Indoors, they only need misting a few times a week and light fertilizer every month.
Gardener Mark Issenberg of Rising Fawn, Ga., said tillandsia is the most popular air plant and is available in many local nurseries.
Issenberg offers the following tips about caring for tillandsias.
1. Tillandsias tolerate a wide range of conditions. They do not need soil to grow in, but they do prefer bright light and temperatures above 40 degrees.
2. The plant blooms about two weeks annually. After blooming, tillandsias produce offshoots or pups, and the parent plants will gradually die off. The pups can be separated by cutting from the parent plant when they are half the size of the parent.
3. The plants can be glued, wired, pinned or tied to driftwood, seashells or baskets.
4. Tillandsias also need plenty of fresh air and humidity.
5. To water the plant, submerge it every two weeks -- or less if dry -- in a bucket of water with a pinch of 20/20/20 fertilizer.