The term "air fern" is used to describe both a live green plant and a coral-based, nonliving, plantlike decoration. Neither are ferns but both do have a fernlike appearance. Living but dormant plants, sometimes called resurrection plants, are often sold as air ferns. When air ferns are presented as needing no care, they are usually not plants at all but the coral, Setularia argenta, which is harvested by boat and specially preserved to resemble a plant. Both the live resurrection plant and the preserved coral type of air fern are easy-care additions to the home. With proper care, both can last for years.
Buy the resurrection plant in its dormant stage. The plants are usually available rolled up into dried balls about 2 inches across. Plants sold as air ferns or resurrection plants are either a fernlike moss native to Texas, Seloginella lepidophylla, or the desert plant Anastatica hierochuntinca. Both plants have developed the same characteristics so they can resist drought. In the absence of rain, resurrection plants can rest, waiting years at a time if necessary, until moisture is again available. Both plants have a maximum diameter of about 12 inches, so purchase as many as needed to fill a planter or basket.
Fill a shallow container with water. Place the dried ball form of the resurrection plant in the container. The container should be at least 12 inches wide for a single plant and wider for several. The container should not be deep enough to submerge the balls, which will float at first. Check the balls periodically to see if more water should be added to the container. Keep the water level constant until the plants are completely hydrated and ready for planting.
Plant the hydrated resurrection plants. In USDA plant hardiness zones 8 through 10, use them outdoors as an easy-care groundcover. The plants will spread and can be a nuisance, so be careful where you plant them. Select a sheltered, partly shady location and well-drained sandy or clay loam soil for best results. Resurrection plants grow up to 4 inches tall and 12 inches wide. Provide regular moisture. Indoors, plant in a fast-draining soil mix in a hanging basket to take advantage of the plant's floppy growth habit.
Coral "Air Ferns"
Purchase coral air ferns in aquarium stores, garden centers or gift shops. The name air fern seems apt because the product has airy sprays that resemble delicate fern fronds. Like all corals, Setularia argenta is a colony of many simple sea animals that live together. The other common name is sea fern, and the most common home uses are as aquarium decorations in a variety of colors or dyed green to resemble a house plant.
Remove the air fern purchased as an aquarium decoration from the package. If any odor is detected, allow the product to air out for a few hours. Rinse carefully as the plumes can sometimes be brittle. Aquarium fern is usually weighted and can be positioned easily in a fish tank by simply sinking it. Alternatively, bury the "stem" end of the product several inches in the aquarium gravel at the bottom of the tank. No further care is needed.
Remove the wrapping from an air fern purchased as a plant substitute. If you notice a strong smell, place the air fern in a room with an open window for a few hours. Then use the product in a dried or silk floral arrangement, or press it into floral foam or floral clay as a base and give it its own basket or container. Never use water on a plant-substitute air fern or the color may change or fade. Dust gently with a feather duster as needed. No other care is necessary.