Are you curious about those odd houseplants that look like pineapple tops, growing without soil? Sometimes called air plants, Tillandsias can do very well in our Midwest homes, adding some pizzaz to your houseplant lineup.

About Tillandsias

There are more than 650 species in the genus Tillandsia, a relative of pineapple in the bromeliad family, that grow on trees or rocks. Their leaves are tough, many times longer than wide and arranged in a spiral. Occasionally, they will bloom, first sending up a colorful flower spike followed by tiny flowers.

The flowers remain for a few days, but the showy spike can last for weeks. After flowering, the plant will die, and new plants will grow from the base. These new plants, called “pups” can be separated or left to create a mounding effect.

All Tillandsias absorb water through hairs on their leaves called trichomes, and only use roots for attachment. Tillandsias that are found in dry, or xeric areas have so many hairs that their leaves take on a silvery cast.

They absorb and hold water very well and are easy to grow in our dry, heated Midwest homes and offices. Tillandsia ioanatha, T. xerographica, and T. tectorum are some xeric Tillandsias that are beautiful and easy to care for as a houseplant.

The leaves of Tillandsias that grow in more wet, or mesic regions are not covered with a thick layer of hair and look smoother and greener. These are a little more challenging to grow in the dry indoors and need to be watered more frequently. Some mesic Tillandsias to try are T. bulbosa, T. andreana, and T. brachycaulos.

Planting ‘air plants’

Tillandsias grow in the air, so you can recreate this by attaching them with glue or wire to a support such as driftwood or rocks; in time they will grow attaching roots. You also can set them in an empty vase or pot, or even on a windowsill. Xeric species often remain too wet

to be kept in a terrarium or even a partially enclosed dome, so save those planters for mesic species.

Taking care of Tillandsias

Despite being called “air plants”, Tillandsias still need to be watered occasionally. Xeric species need to be watered about every other week, while mesic ones need water about once a week or more. Curling leaves are a sign that you need to water more often.

Water by either soaking or running water over them, for about a minute for xeric and longer for mesic plants. Let them drain and dry upside down for an hour or so, especially if they are returning to an enclosed space.

Every few months pour houseplant fertilizer at one-quarter strength over your plants instead of water. Xeric Tillandsias need a few hours of bright light every day, from a south or west window while mesic Tillandsias grow best in filtered, indirect light.

Try your hand with Tillandsias to add some tropical punch to your houseplant collection! For more details, see go.illinois.edu/AirPlants and njaes.rutgers.edu/plant-of-the-month/tillandsia.php.

• Sue Styer is a certified Master Gardener and Master Naturalist volunteer with University of Illinois Extension serving DuPage, Kane, and Kendall counties