A Question of the Week

air plant

If you have visited a garden center in the last few years, you have undoubtedly stumbled across an interesting looking display of air plants. Air plants are stiff-leaved, rosette-forming plants of the genus Tillandsia, which are native to the southern U.S., Central and South America and the West Indies. They belong to the same plant family as bromeliads and are restricted to warm areas with relatively humid weather.

Air plants are unique because they get all their water and nutrients from the air through special scale-like structures on their leaves. Air plant roots are designed to keep plants anchored to their growing surface — either trees or rocks depending on the species and its habitat. Most people grow air plants for their curious-looking foliage, though they will flower if growing conditions are just right.

Choose the Right Species of Air Plant

Air plants need different care depending on where they grow naturally in the wild. Air plants that are native to desert regions need a lot of sun, lower humidity and more infrequent watering. Those from rainforest environments require high humidity, shelter from the direct sun and careful attention to watering. All the Tillandsia species that are sold as houseplants are fairly resilient and adaptable, but they will perform best if you cater your care to their specific needs.

If you do not know the native region of your air plant, you can make an educated guess based on its traits. Air plants from dry, desert areas tend to be silver-green with scaly or fuzzy, flattened leaves. Those from humid, tropical places are dark green, less scaly and are more likely to have curved leaves. Some species will fall in-between. Most houseplant owners will probably find it easiest to care for silvery, fuzzy air plants, because these are most forgiving when it comes to watering.

Growing Requirements

In general, air plants need bright, indirect light. East and west-facing windows are perfect for year-round growth, while south-facing windows are an excellent location in the fall, winter and spring, but they may get too hot in the summer months. It is unlikely that air plants will do well in windows with a northern exposure or interior rooms without a light source. Though they might look nice on the coffee table, they won’t usually hold up for very long or put on much growth in this location.

Warm temperatures are also important for keeping air plants healthy. Like most houseplants, air plants prefer the indoor temperature to fall between 65 and 85℉ in the daytime, and between 50-65℉ at nighttime. At lower temperatures, growth tends to be poor, and plants are more prone to rot.

Watering Air Plants

Properly watering air plants is absolutely essential, as incorrect watering is one of the top reasons growers are unsuccessful with them. Because air plants absorb water and nutrients through their leaves, they need to be watered frequently and consistently. Slightly rolled or curled leaves indicate it is time to water, and brown leaf tips are a sign that plants aren’t getting enough water.

One way to meet plant needs is to mist them with a spray bottle every other day. This method works well for air plants from arid regions, but is less effective for those from rainforests that have higher water needs. If misting doesn’t work for you, another option is to rinse plants with tepid water under the faucet a couple of times a week, which works for those with wells, as air plants can be sensitive to chlorine and fluorine. Perhaps the best option is to soak air plants in tepid water for 10-20 minutes once or twice a week. Dark green, less scaly air plants will benefit the most from this treatment. A quick dunk underwater is more than enough for silvery-green foliage varieties.

As important as watering is, many air plants meet their end from over-watering. Air plants will likely rot if they are watered too frequently, stay wet for too long or if water is allowed to collect at the base of their leaves. Ideally, air plants should be kept in a warm location with good air circulation so that their foliage will dry within four hours after watering. After soaking or rinsing, it is also helpful to suspend or rest plants upside down for a few seconds to allow excess water to drain away from their crowns.

Air plants should also be fertilized about once a month or so. The easiest way to do this is to soak them in a diluted fertilizer solution for a few minutes. Any water-soluble houseplant fertilizer will do, though it is possible to buy specific fertilizers formulated for bromeliads and air plants.

Displaying Air Plants

Displaying air plants is really where most of the fun comes in. One popular option is to place them inside of glass globes. Other possibilities include attaching them to bark or cork with wire or glue, or displaying them in dishes of decorative pebbles. Air plants can be grown on essentially any surface that dries quickly and makes it easy to water. You are only limited by your own creativity!

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