This is the name given to all the plants in the family Bromeliaceae. The most well known of these is probably the Pineapple. They have their origins almost totally in the New World, particularly places such as Mexico, Costa Rica, Brazil, Peru and Chile. The range in habitats is enormous as some inhabit dense steamy tropical rain forest while the Tillandsias or Air Plants are found high up in the rarefied air of Peruvian mountain ranges at heights of 4000 m (13,000 ft). These plants are mostly epiphytes growing on trees or rocky cliffs. There are some which are terrestrial or ground growing such as Ananas (Pineapple) and Bromelia. Cryptanthus or Earth Stars grow in the ground or over the stumps of trees.
Temperature and the amount of shade needed depends a lot on origin. Plants such as Puya which have rough leaves need full sun and a cool house, whereas those such zsAechmia, Neoregelia, Billbergia and Guzmania which have shiny or soft leaves need more shade and warm or tropical conditions.
Most of us will grow even thespecies in pots as they demand far less attention this way. They prefer an open . Proprietary peat-based composts with extra coarse peat and added grit are ideal. Allow the plant to grow and become quite potbound as they tend not to need to produce an extensive root system. After flowering the plant will die but only slowly and not before it has produced one or more offsets or ‘pups’ as they are called amongst enthusiasts. When the older plant is unsightly the pup can be taken off. In some cases they will have their own roots but sometimes they must be treated as a large cutting.
While growing epiphytically in the wild, the air around is very moist and the plants whose leaves form an urn will catch drips of moisture from the leaves above. They are not used to growing in a wet compost and will resent this.
Allow the compost to begin to dry out between waterings but allow water to collect on the urn. A weak foliar feed is the best method of feeding and this should be given every two weeks throughout the growing season. Damp down regularly but with a fine mist that will not soak the compost.
It is possible to encourage plants to flower by sealing them in a polythene bag, which has been inflated with air and contains an apple, for at least a week. Supposedly the ripening apple gives off ethylene gas and within a couple of months the plant will flower. I have never tried this, preferring my plants to flower naturally, but pineapple growers treat their plants with an ethylene-based product which allows them to control the fruiting. The same product is used by growers to bring pot plants into flower for the pot plant market.
Tillandsias or Air Plants need more specialist care as they will not tolerate being grown in. There are companies which sell plants and all manner of attractive tropical woods, shells, etc. on to which to attach them. I prefer to find my own piece of driftwood or bogwood but not just any old dead branch as these decay too quickly. The plants are stuck to their branch by means of a silicone glue similar to that which you might use for sealing a bath. This is also available with the plants. Unfortunately, the glue takes an hour or so to set so it is necessary to secure the plant with a piece of cotton while this is taking place. I shall not pretend that these plants are easy to keep. There is a delicate balance between stopping them from drying out and getting them so wet that they rot. Spray them lightly with a fine mist spray at a time of day when they will dry out quickly. Keep the atmosphere around them as humid as possible but ventilation should be good and a minimum temperature of 13°C (55°F) is ideal. During the summer the fine spray will probably have to be daily if the weather is hot and sunny. However, during winter and damp weather leave four or five days between spraying. Lower down on the branch other bromeliads such as Urn Plants can be fixed with some sphagnum moss around their roots with perhaps some Earth Stars at the very bottom. Bear in mind that these will require a more thorough watering than the Air Plants.
If you only have a cool house it is possible to grow Puya alpestris which makes rather dense rosettes of leaves and can take up a lot of space. However, it is well worth while when the spectacular flower spike is sent up some 1.2 m (4 ft) with its curious blue-green flowers with orange anthers.
Aechmea fasciata is the Urn Plant with its attractive silvery marked leaves and pale pink flowers. I would grow Neoregelia carolinae ‘Tricolor’ for its leaves striped with creamy-yellow and the bright pinky-red centre. As the leaves grow older they become more and more pink at the centre. Vriesia splendens has dark stripes across its leaves and regularly produces a long red flower spike. Ananas comosus ‘Variegatus’ is the Variegated Pineapple which is a superb plant with wide creamy toothed margins to the leaves. Flowers appear on a long stalk which are followed by pinkish fruits. Billbergia nutans can tolerate cool conditions in winter and has many leaves which are greyish on the underside. Greenish-blue flowers emerge from pink bracts during spring.