Bromeliads
Growing Bromeliads Indoors
Many gardeners have discovered that although bromeliads have exotic tropical foliage and flowers, they are not difficult to grow indoors. The most distinctive feature of Bromeliads is the cup shaped rosette of leaves, which holds the water that nourishes the plant. Originating from the tropics, most bromeliads are epiphytes (air plants), and grow suspended in trees in their nature habitat, gathering moisture and nutrients from rainfall and particles in the air.
Bromeliads are excellent indoor plants. They have colorful, long-lasting inflorescences and some have brilliantly colored foliage as well. Bromeliads also readily adapt to the unfavorable growing conditions that exist in most homes.
Although many bromeliads are epiphytic, living on branches and trunks of trees or on rocks in their native habitat, most can be grown in containers. Clay and plastic pots are equally satisfactory as containers unless plants are large, in which case the heavier clay pot is more stable. Because plastic pots retain moisture longer than clay pots, plants grown in the former need watering less frequently than those in the latter. Epiphytic bromeliads can also be grown in perforated plastic baskets and clay pots like those used for other epiphytic plants such as orchids.
Some epiphytic bromeliads, such as the gray-scaled Tillandsia, grow poorly if planted in a conventional potting mixture. They grow best in a medium such as tree-fern bark, cork-oak bark, or on a tree-fern slab, or pieces of wood. To mount a plant on one of these materials, wrap the base of the plant (including roots, if any) in sphagnum moss, and tie the wrapped base to its support by winding plastic-coated wire around the moss and the supporting material. Fasten the ends of the wire firmly but in such a way that it can be easily untied. Hang the mounted specimens in a convenient place. Spray the sphagnum moss and plant with water frequently enough to prevent complete drying of the moss.
After supportive roots grow over the sphagnum moss and around the mount, remove the temporary wire. To keep the plant alive and healthy, water the plant, its roots, and the supportive materials twice weekly throughout the year. Water can be applied as a spray or the entire mounted plant can be submerged in water for a few minutes. The humidity around plants will influence their need for water. The humidity in a home, which is heated during the winter months or cooled with air-conditioning during the summer months, can be very low and plants may need to be watered more frequently than those grown in a moist environment.
Growing Bromeliads Outdoors
Bromeliads can be used in the landscape in frost-free areas of the state or grown in containers that can be moved indoors in areas where freezes occur. Since bromeliads require minimal care, they are an asset in the landscape.
In areas where frost and freezing temperatures are common, covering with plastic or cloth may offer some protection. However, it is an extremely tedious job to cover the plants, and the covers are unsightly. In addition, mechanical breakage of leaves often occurs. A more practical way to prevent cold damage is to grow bromeliads in containers with a potting mix and sink the containers into the ground. When freezing temperatures are predicted, pull the containers out of the ground and move them into a garage or other protected area. While indoors, the plants should receive some light during the daytime. When temperatures are above freezing and no more frosty nights are predicted, the plants can be placed back into the landscape and mulched to hide the pot edges.
Care and Culture
Light
Bromeliads tolerate a wide range of light intensities, including low light, for long periods without ill effects. The plants, however, will look better when they receive proper light.
Although optimum light levels vary considerably, the following characteristics are helpful in selecting a spot for a particular plant. Generally bromeliad species with hard, thick, gray, gray-green or fussy foliage withstand the highest light levels, while species with soft, green, thin leaves grow best under lower light levels. A general recommendation is to grow bromeliads where the light level is approximately 1,500-foot candles or where orchids grow well. In a home, a window with a southern, eastern or western exposure is satisfactory for bromeliad growth, but most species must not be exposed to the direct rays of the sun.
In most instances, a bromeliad will indicate by its growth habit whether light levels are satisfactory. A yellowish or pale green plant may indicate that the light level is too high. Conversely, a darker green than normal, with a more open or elongated shape, may indicate low light levels.
Temperature
The majority of bromeliads are tropical or subtropical. In a home environment, however, bromeliads do best at 70-75 degrees during the day and between 60-65 degrees at night.
Humidity
Most bromeliads grow best indoors at a relative humidity of 40 to 60%.
Air Circulation
Bromeliads, due to their epiphytic nature, require good air circulation. Fresh air supplies them with carbon dioxide and moisture.
Water
Bromeliads are extremely tolerant of low-moisture conditions and will survive prolonged periods of drought. Most of the problems encountered with bromeliads are usually associated with rot caused by over watering. Growing these plants in light, porous potting mixes that drain rapidly should help prevent this problem.
Bromeliads grown in a potting mix or in the landscape should be watered when the soil surface feels dry. Plants grown in pots should be watered thoroughly, until water runs out of the bottom of the pot and then not watered until the medium surface feels dry. Under normal household conditions, watering thoroughly once a week is usually sufficient. In homes where the relative humidity is low (during winter months and in air-conditioning) plants must be checked and watered more often.
Epiphytic bromeliads, such as those found in the genus Tillandsia, are often grown secured to a board or bark. Because these plants have no distinct cup to collect water, they absorb moisture from the air through their scaly leaves. Unfortunately, in an indoor situation, where the humidity is usually very low, they are unable to obtain adequate moisture from the air. Moisture can be supplied to these plants by misting or dousing them in a container of water daily.
Fertilization
Active growing bromeliads respond to light applications of fertilizer. During the winter months, or under conditions of low light, they require little or no fertilizer.
Propagation
Remove mature offsets and a sizable section of roots from large plant in a well drained potting medium in a shallow container.