Anita Morton - Growing Gardens
Bromeliads depend entirely on the scaly surface of their stems and leaves to collect moisture and nutrients from the air. The ones we grow most commonly here dont actually root in the ground at all in their native habitat. These species are from Central and South America, where they grow on the branches of trees. Their roots dont collect water or nutrients, but only anchor the plant to the tree. In our climate they can be grown in this way just secure the young plants in a tree fork with twine until their roots start to cling.
Bromeliads also do well in the ground provided they have a loose, airy growing medium, such as a mixture of leaf mould and bark chips, or are planted on a mound or slope. They are generally happiest in dappled light, so a spot under a tree suits them well. Knock the plant out of its pot and sit it on the ground, then pile up leaf mould or well rotted wood chips around the roots. Keep the plant moist while it gets established. Bromeliads appreciate a little extra water in very dry weather, and a splash of weak fish emulsion on the foliage once or twice a year.
Established plants should have strong pups or side-shoots at this time of year. These can be gently twisted away from the parent plant and replanted separately. They can also be potted up in hanging baskets or for indoor plants. Use a mixture of two parts potting mix and one part peat moss or coconut peat. In some species of bromeliads the main growth of the plant dies after flowering. If your broms are looking seedy, they are probably of this type, and you should trim away the ratty looking old parts of the plant now to make room for the new growth.