Air plants are attractive plants that don't need soil or a growing medium to grow -- they can grow on other plants or in the air, getting all the water and nutrients that they need through their leaves from the air. They are also called epiphytes and are perfect plants for the beginner indoor gardener!
In nature, they often grow on trees, but they aren't parasitic and don't harm the host tree.
One of the most common epiphytes that you've probably seen is called tillandsia, belonging to the Bromeliad family. Here's a picture:
Because tillandsias mustn't be planted in soil, you can be very creative with how you mount them. Here are some popular ideas:
Tillandsias flower once in their life. When your plant flowers, it will produce "pups". When these offshoots reach half the length of the mother plant, you can separate them. Often when tillandsia blooms, the leaves will turn orange or red.
Airplants are very hardy and fairly low maintenance. The instructions aren't suitable for all tillandsia species. Some have different needs and you should find out about the ones you have bought. The guidelines I give should work for the most common species.
It's a bonus that it's difficult to overwater them because they aren't in pots. Water them by holding the plant under the tap until wet, or even submerging the plant in water. Shake them to remove excess water before replacing them on their mount.
Bromeliads with thicker leaves don't need as much water. Make sure there is no water in the nooks and crannies of where the leaves meet the stems. A good shake helps with this.
Water about 2 to 3 times a week, but this depends on the variety you have. Water in the morning so the plants can dry quicker. We don't want them to stay wet longer than two or three hours.
If you go on holiday, soak your plant for abount 4 hours a couple of days before you leave and then again for 12 hours as close to your departure as possible. When you return, soak for 12 hours and then 4 hours a couple of days later. Then continue with the normal watering cycle I've described.
Don't put them in direct sunlight or they might die. Partial sun is fine. Good indirect light is best.
You don't really need to fertilize tillandsias, but it does help to speed up growth, producing better flowers. It will also result in more pups.
Fertilize using 1/4 of the strength suggested on the label. This is because airplants are very prone to being over-fertilized! Fertilizer should be liquid soluble and have an NPK (Nitrogen, Phosphorous, Potassium) ratio of around 10-15-20. Take it easy with the fertilizing!
Trim away damaged or brown leaves to keep it looking healthy.