About air plants

Natural habitat

Air plants from the genus Tillandsia are naturally found in the Americas, all the way from the southeastern United States down to central Argentina (Granados Mendoza et al., 2017). Their natural habitats can vary from shaded rainforests to arid, exposed semi-deserts.

What all air plants do have in common is that they don’t grow in soil. Instead, they have evolved to grow in trees in a non-parasitical manner or on rocks.

This is something quite typical of the overarching family they belong to, the Bromeliads (Bromeliaceae).

Description

This is a funky houseplant if there ever was one! Some species look truly alien, and there are loads of variation within the genus Tillandsia—not too surprising given the fact that they occur in so many different habitats, but it makes it difficult to provide a general description.

Still, there are a few things most species have in common:

• Like many other members of the Bromeliad family (including Guzmania), the majority of air plant species grows in a rosette fashion. They feature a sort of central “cup” that water collects in.
• Air plants don’t grow in soil, but they can have roots. These aren’t meant to absorb moisture or nutrients, but rather, to help the plant latch onto surfaces like tree branches or rocks. (Aerial roots are also found in creeping epiphytes like Syngonium podophyllum and Hoya kerrii.)
• Air plants flower (and yes, many do so inside the home as well!). Their blooms are usually very colorful, often pink, purple, and yellow, and they result in little seed parachutes that are naturally carried by the wind. 
• Also typical of the family Bromeliaceae is the fact that many air plants grow in a clumping manner. A mother plant eventually dies off after flowering, but not before producing plenty of offsets. This can lead to impressive air plant balls!

Uses and cultural significance

As mentioned earlier, Tillandsias like Spanish moss are an integral part of that “Southern atmosphere” you get in states like Georgia and Texas.

Be careful though: Anyone in these regions will tell you to stay away from these plants, as they carry chiggers, which are annoying bitey bugs. 

In Central and South America, locals have long used different Tillandsia species for all sorts of purposes. According to a 2019 paper by Estrella-Parra, Flores-Cruz, Blancas-Flores, Koch, & Alarcón-Aguilar, some of these uses include:

• Historically as fibers in pottery
• As cattle feed (Tillandsia usneoides or Spanish moss)
• As decorations in Aztec temples
• For wrapping fruit and fragile wares as well as stuffing pillows and blankets (Tillandsia usneoides)
• As part of culturally significant magical rituals
• As a natural medicine for ailments like hemorrhoids, ulcers, inflammation and loads more

It has even been suggested that some Tillandsia extracts have uses in anti-aging and other cosmetics.

The massive-scale cultivation of air plants as houseplants is relatively new. Some growers saw them as a good alternative to other Bromeliad species, as they don’t tend to collect standing water, which can be a mosquito risk (Dematte, 2005).

Air plant varieties

Tillandsia is not a small genus: There are around 650 species out there (Granados Mendoza et al., 2017).

Even in your local plant store, you’ll sometimes be able to find quite a few different air plants. All are specifically adapted to their natural habitat, which is why the different species can look quite different from one another.

Roughly speaking, you can divide Tillandsias into two groups: xeric and mesic.

Xeric Tillandsias are found in sunnier habitats that are prone to drought and fluctuating temperatures (think deserts and mountain areas where humidity is low and tree cover is sparse). They’re often growing on rocks at higher altitudes and are adapted to brighter, drier conditions.

Xeric air plants can be recognized from their fuzzier appearance. This fuzz actually consists of trichomes, the small silvery “hairs” an air plant uses to absorb water. Trichomes regulate the amount and timing of water allowed into the leaf and can protect the plant from sunburn.

Not only are xeric Tillandsias fuzzier than their mesic cousins, but they tend to be grayer in appearance as well.

Mesic Tillandsias are mostly smooth in appearance (or at least have fewer trichomes), as the species naturally get plenty of air moisture from their moderately wet rainforest environments.

They can usually be found in cooler, moist habitats with more humidity and less direct light. (I’ll get back to this in the sections on light and watering, as it does influence the amount of light and moisture an air plant needs in the home.)

Mesic air plants tend to be on the greener side compared to xeric species, but just because they’re a “wet” plant doesn’t mean they actually like to stay wet all the time. It simply means they can tolerate more frequent watering.

Now that you know the differences between xeric and mesic Tillandsias, let’s discuss a few of the most popular air plant species—the ones you’ll likely find in your favorite plant store.

• Tillandsia xerographica: Sometimes referred to as the queen of Tillandsias, this rosette-shaped species can grow very large (and quite expensive!). It naturally occurs in dry forests in Central America, where it receives plenty of light. This makes it a xeric species. It’s one of my absolute favorite varieties of Tillandsia—in fact, I carried a single stunning xerographica as my wedding bouquet!
• Tillandsia ionantha: This is definitely the one I see most often in plant stores, and you might know it as a sky plant. The small Tillandsia ionantha is naturally green, but selective cultivation has led to red-tipped varieties as well. This, combined with its frequent purple flowers, makes it a real show-stopper! It’s a xeric species naturally found in Central America.
• Tillandsia stricta: Another popular species that has resulted in a variety of different cultivars. It’s found in much of South America and its habitat varies, which is why there are a few subspecies with different appearances.
• Tillandsia bulbosa: A decidedly mesic species, this one is naturally found in much of Central America as well as parts of South America. It’s a fun option for beginners and there are a few different cultivars!
• Tillandsia cyanea: Okay, this isn’t technically a Tillandsia—or not anymore in any case. It was recently recategorized into the genus Wallisia, but given its beautiful flowers, it’s definitely still worth a buy if you like Bromeliads. Unlike the other air plants on this list, it’s grown in soil.

Caring for an air plant

Light and temperature

In the home, most air plants will generally do fine in bright indirect light. This being said, depending on the species, you can opt to give them a little more or less.

Xeric air plants hail from areas that tend to be more exposed, which means they’re adapted to receiving more direct sun than their mesic cousins.

Basically, the fuzzier your air plant, the more xeric it is, and the more direct sun it will prefer. 

In terms of temperature, the ideal range will also depend on the species of air plant you’ve got on your hands. Room temperature should be fine, though 50°F is the lowest most will be able to take: any colder and they can start suffering, or at least stop growing.

When it comes to warmth, they can handle pretty much anything you can throw at them, as long as they’re not being literally burned by the sun. 

Water and humidity

If you’re not familiar with growing air plants, this is probably the bit you’re most confused about. But no worries, it’s not that complicated!

Instead of keeping your plant hydrated by pouring water into the soil, you can do so by spraying, dunking, or soaking them. 

The preferred method and frequency depend on factors like the type of air plant, airflow levels, amount of light, and air moisture. You’ll have to experiment a bit to figure out what works for your plants!

My own preferred method is to soak most (but not all) of my mesic air plants in a bowl of water for half an hour every 10 to 14 days (depending on the season). Between soaks, I lightly spray them with water whenever I remember to, as they tend to be thirstier.

For my xeric plants, I dunk or spray them (never soak) every 10 to 14 days and keep an eye on them in between waterings.