I am looking for an interesting plant to give a good friend who is into gardening, and I’d like a suggestion. The plant will be grown indoors.
—Diana Perez, Naperville
I would consider purchasing a plant from the Tillandsia genus. They are commonly known as air plants and can be found in the jungle, rainforest and arid desert environments from sea level to high mountain regions. Most species of Tillandsia use their root systems to attach themselves to trees or rocks and absorb moisture and nutrients through their leaves, which classifies them as epiphytes. The plants absorb water through small scales on their leaves that give many air plants their silvery sha or gray appearance. textures, blooms, and colors in this group of plants. Many undergo a dramatic color change as they go into flower. Tillandsia are relatively inexpensive, adaptable plants that tolerate a wide range of environmental conditions and require minimal care, so are well suited to home gardeners.
Tillandsia grow differently than most other houseplants, so they can be a bit confusing at first. You do not pot them up into a container with a growing medium. Instead, use glue, wire, fishing line, twisty ties, nails, and staples to attach them to a support such as driftwood or metal frames, or put them into a container such as a glass globe without any growing medium. The plant will eventually attach roots that anchor it to the mount. If the plant has a large enough root system , a heavy staple gun can be used to staple the roots directly to the mount. Nails and staples can only be used on plants with a good root system or woody stolon. Use waterproof glue and let it cool briefly before attaching plants if you are using a hot glue gun. Avoid using super glue or copper wire to avoid damaging or killing the plants. Air plants should not be put in containers that hold water, since they need to dry out. If you do place your plant in something that holds water , empty out the excess water after watering your plant. Do not surround your plant with moss that holds water that might eventually cause the plant to rot. Spanish moss, however, works well to camouflage the roots and plant attachments since it is open and airy and does not hold moisture.
Position Tillandsia so that they receive bright, filtered light while avoiding direct sun. In general, the higher the humidity in your space, the more light can be tolerated by the plants. The silvery-leafed varieties can usually be grown in full sun outdoors. If the air in your home is dry, it is best to submerge the plant in water for two to three hours every two weeks or so. If this is not feasible, use a soaking mist two to three times a week — more often in a hot, dry situation and less often in a cool, humid one. Do not use distilled or softened water on the plants. Filtered water, tap water that has sat long enough for the chlorine to dissipate, bottled water or reverse osmosis water is best.
Many people do not water these plants enough. The leaves will develop an exaggerated curl or roll if they are kept too dry. Ideally, give your plants enough air circulation and light to dry in less than three hours after watering. Spray misting can be beneficial between regular watering. In a very sunny spot indoors, they may need daily misting or weekly soaking depending on which method you prefer. Provided the atmosphere is not too dry (as in an air-conditioned home), they can survive with water misting and the occasional soaking. It is better to water in the morning than at night since Tillandsia can absorb carbon dioxide from the air at night instead of the daytime. This process is impeded when the plant foliage is wet. Purchase fertilizer that is formulated for air plants , as they absorb nutrients through their leaves. Fertilizers for orchids or bromeliads will also work well. Apply these at quarter to half strength.
For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at email@example.com. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.