Tillandsia, or air plants, are curious plants. Because they are not planted in soil and sometimes don’t have roots, you might think they don't need water. But these plants take in their water and nutrients through trichomes rather than roots. Trichomes are modified scales or hairs on the entire leaf surface. Roots, if there are any, serve another purpose--they anchor the plant to tree branches or rock faces, enabling access to bright sunlight.

Tillandsias are epiphytes, like the majority of plants similar to orchids (although they are not in the same plant family as orchids). There are two types of Tillandsia--xeric and mesic. Xeric types (xerophyte: from Greek xero meaning dry and phyto meaning plant) live in dry climates. Mesic plants (from the Greek word for middle) are suited to moderate or average amounts of rainfall and humidity.

The different appearance of xeric and mesic air plants is due to their trichomes. Xeric varieties have large, dense, feathery trichomes which protrude to soak up limited water and nutrients. These trichome structures enable them to live in hot, dry climates. Xeric Tillandsia appear fuzzy or furry, with a whitish, gray or silvery coloration (sometimes they look like sugar crystals). This light coloration reflects sunlight, protecting these dry-zone plants from harsh sun. Their trichomes can lie flat or parallel to the leaf surface, serving as miniature parasols shading the plant from sunburn. Many xerics have curly leaves and a bulbous shape. Some xerics coil tighter when they are drier, making for bizarre-looking plants. Water xeric air plants less frequently than mesic ones and give xeric types brighter light (more direct sun). 

Mesic trichomes are smaller and less prominent than xerics’. Mesic leaves are smoother and more lustrous, slicker and greener.

There are some 600 species of Tillandsia, the largest genus in the bromeliad family. One rootless variety is Spanish moss, T. usneoides. Tillandsia grow very slowly. They can produce new plants called pups or offsets. Keep pups near the parent plant as long as possible to nourish them. Tillandsia seeds are attached to cottony tufts (comas) which ride on air currents. Scented varieties include T. duratii, with purple flowers and a grape soda scent, and T. crocata, yellow-flowered with gardenia or jasmine scent. A Tillandsia with unusual growth is T. intermedia, which sprouts new plants from inflorescences in a process known as viviparous reproduction (like an endless daisy chain).

For both mesic and xeric varieties, bright filtered light is best, in a location near a window with southern, eastern, or western exposure.

For mesic plants, watering methods include misting, dunking, and soaking. To dunk, rotate plant under a stream of water in sink/shower or outside hose for a few seconds, 2-4 times per week. Soaking to revive a thirsty plant may be done once a week in tap water for 1-2 hrs. For xeric varieties, mist every two days to once a week, or rotate under a stream of water every 7-10 days. Do not wet flower petals or they will not last. Some xeric Tillandsias have a very dense structure with a lot of undulating leaves, so be careful to moisten all parts. Then drain well by turning. Standing water will rot your air plant.

For fertilizer, 10-8-6 or balanced water-soluble organic fertilizer is best. Tillandsia do well in normal room temperatures, not below 40°F.

The name “air plant” can refer to any plant that grows epiphytically, meaning without any soil or substrate, usually upon other plants but not feeding on them.

For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service