Air plants are Tillandsia, a genus of epiphytic bromeliads in the pineapple family. NC State Extension counts more than 600 species; UF/IFAS and Clemson say over 500. They grow without soil. Their roots only anchor the plant, and silvery scales on the leaves absorb water and nutrients.
UF/IFAS makes a useful point for buyers: indoor care is about the same for most species, so choose by the look you want. The exceptions are size, and how much water a large plant holds in its centre.
Common air plant types compared
| Air plant | Size | Look | Watering (source) |
|---|---|---|---|
| T. ionantha | 15–30 cm (6–12 in) tall | Small rosette of grass-like, silver-scaled leaves; top leaves turn bright red before blooming; blue-violet flower | Regular, thorough watering; shake out excess (NC State) |
| Giant air plant (T. xerographica) | 30–90 cm (1–3 ft) tall and wide | Large, silvery grey, curling leaves | 15-minute soak every 1–2 weeks; monthly in winter; dry upside down (NC State) |
| Spanish moss (T. usneoides) | Hanging strands 25–90 cm (10 in–3 ft) | Pendulous silver stems and leaves; no roots as an adult | Occasional watering indoors, drying between; needs high humidity (NC State) |
| Ball moss (T. recurvata) | Small, round clumps | Grey tufts on branches and wires | A common wild Florida species (UF/IFAS) |
| Southern needleleaf (T. setacea), broad needleleaf (T. simulata), Bartram’s air plant (T. bartramii) | Small | Thin, needle-like leaves | Florida natives; do not collect from the wild (UF/IFAS) |
Other species often sold include T. caput-medusae, T. bulbosa, T. streptophylla, T. stricta and T. tectorum. We have not found extension profiles for these, so we do not give separate care claims; follow the general care below.
Tillandsia ionantha and its cultivars
T. ionantha is the small air plant sold in most shops. It is native to Mexico and Central America, and its name means “violet flower”. NC State describes it as easy to grow, living several years and forming a clump of pups.
When it is about to bloom, the top leaves turn bright red. The flower is blue-violet on a short spike with red bracts.
Cultivars listed by NC State:
- ‘Fuego’: fiery red colour in plenty of sun.
- ‘Rubra’: red leaves, in a short “soft” form and a more vertical “hard” form.
- ‘Guatemala’: spiky, bright green, turning light pink to red.
- ‘Mexican’: deep green turning red.
- ‘Druid’: white flowers.
- ‘Scaposa’: tall and unusually shaped.
- ‘Vanhyningii’: thick leaves in a star-like pattern.
NC State notes it is not troubled by pests or diseases.
Giant air plant (Tillandsia xerographica)
One of the largest air plants in cultivation, native to dry tropical Mexico, Guatemala and El Salvador. It forms a silvery grey rosette of curling leaves up to 90 cm (3 ft) across and grows slowly.
NC State’s care notes:
- Light: bright light, but not full sun; a south-facing window should be enough.
- Water: soak for 15 minutes every one to two weeks, and monthly in winter. Heating and air conditioning dry the air, so indoor plants may need more.
- Drying: shake it out and dry it upside down after soaking to prevent crown rot. Its tight centre holds water.
- Flowering: it blooms once in its lifetime, sending up a flower stalk 30–90 cm (1–3 ft) tall with green to yellow or orange-red bracts.
Spanish moss (Tillandsia usneoides)
The grey strands on live oaks in the southern USA are an air plant. Adult plants have no roots. NC State notes it needs high humidity and pollution-free conditions, and can be grown indoors with bright light and humidity. Water occasionally, letting it dry between waterings. Propagate by tearing off a piece and draping it on a support.
Watering: soak, mist and dry
The three extension sources agree on the principles and differ on method:
| Source | Method | Frequency |
|---|---|---|
| NC State (genus) | Plunge the whole plant in water or hold it under a running shower | At least once a week |
| Clemson (HGIC 1515) | Mist well, or submerge for 20–30 minutes | Once a week |
| UF/IFAS | Mist until water runs off the plant | Once a week |
Whichever method you use:
- Drain it. Clemson advises gently shaking off water and turning the plant upside down to drain, because water in the centre can cause rot.
- Let it dry between waterings. Good air circulation helps the plant dry and prevents disease.
- Watch the leaves. Curled or rolled leaves, dull colour and brown tips mean it needs more water, according to Clemson.
Water quality matters too. See our air plant water quality guide.
Light, feeding and display
- Light: bright, filtered light near an east, south or west window, but not direct sun (UF/IFAS, Clemson). NC State notes most species need high light to flower, and that LED grow lights can supplement.
- Feeding: optional. Clemson suggests a bromeliad fertilizer at one quarter strength once a month; NC State suggests liquid fertilizer at half strength or less.
- Mounting: wood, cork, bark, shells, rocks or a shallow dish. Glass globes work if they get light and air. Whatever you use must not hold water. UF/IFAS suggests wire or glue (let hot glue cool slightly).
After it blooms
Air plants bloom once. UF/IFAS and Clemson note the mother plant slowly dies after flowering while pups grow from its base. Leave the pups attached to form a clump, or remove them once they are a reasonable size to grow on separately.
Buying responsibly
UF/IFAS warns that Florida’s native bromeliads are threatened by collection, development and the invasive Mexican bromeliad weevil, and asks gardeners never to harvest air plants from the wild. Clemson advises buying only nursery-propagated plants.
For pet safety, NC State lists no toxicity for Tillandsia, and the ASPCA has no entry for air plants. See the air plant hub for common problems.
References
- NC State Extension Gardener Plant Toolbox: Tillandsia (genus), Tillandsia ionantha, Tillandsia xerographica, Tillandsia usneoides
- UF/IFAS Gardening Solutions: Air Plant – Tillandsia
- Clemson Cooperative Extension, B. H. Smith (HGIC 1515, reviewed 2021): Air Plants