Bromeliads are members of the lily family, and are native to tropical and subtropical regions of North and South America where they have adapted themselves to make the most of their surroundings.
They are diverse plants that can have unusual plant forms, colors and markings, and can vary in size from less than 25mm (1") wide to over 10m (33ft) tall.
Scales on their leaves act as moisture absorbing organs that pull water from the air.
Many bromeliads have adapted their root system for holding onto branches of host trees, and not for gathering moisture and nutrients through an underground root system as most plants do.
Some have developed the ability to absorb nutrients from rainwater captured in the central rosette of their leaves, and others trap moisture from the air and gather nutrients from any pieces of debris that fall around them.
Most prefer bright filtered light rather than direct sunlight.
This adability makes it unecessary for growers to replicate the plants original environement.
With a bit of care plants will make the necessary adaptions to suit their new environment.
This extra care can take the form of monitoring and manipulating the watering, misting, ventilation and temperature.
If plants have been purchased locally the chances are that only varieties that have been collected at high altitudes will be available, meaning that they should be relatively easy to grow in a cool greenhouses.
If the plant doesn't seem to want to bloom, try triggering the process by enclosing it in a plastic bag with a ripe apple.
The ripe apple will release ethylene, a gas that encourages ripening or blooming.
Keep the plant/s out of the direct sun for a week.
Potted bromeliads prefer a relatively coarse peat-based free draining potting compost, or a purpose blended orchid mix.
Most types of bromeliad do not become root bound, making it unnecessary to re-pot them.
When they finish blooming, the parent rosettes die off, and the offsets formed at the base of the parent plant, can be re-potted separately to make more plants.
Coarse Compost mix
These must not be detached until their rosette is several months old and has developed the shape of the adult.
Take them, with some roots and pot them shallowly in a coarse, peat-based potting compost with a bit of added perlite to provide aeration or specialist orchid mix.
Watering can be critical and depends on type of plant, compost used, humidity, light and the ventilation available.
Where plants are equipped with a cup this should not be allowed to become empty.
If possible use rain water, alternatively cooled boiled water.
Using tap water can intoduce to the bottom of the cup resulting in a build up of salts which can damage (burn) the centre of the plant/s
If there is no alternative flush out the cup regularly to prevent such a build up.
Those without water-holding rosettes should have the compost kept moist but not wet, allow the surface of the compost to become dry when touched before watering.
Plants may require misting about twice a week in addition to watering, in order to prevent drying of the leaves caused by low humidity.
Air plants such as Tillandsia, i.e. those that are grown attached to something like a piece of wood rather than potted up, should be misted several times a week.
During the winter months when the central heating system tends to dry the surrounding atmosphere spray more frequently.
Alternatively, stand them on a humidity tray, or support with a moss covered pole.
Heat, Light and Ventilation:
Good light is extremely important to growing bromeliads, it might be said it is synonymous with the quality of their colouring.
Growing indoors can present some problems when it comes to providing ideal light conditions, although there are some bromeliads that are more suitable to normal indoor lighting than others.
Idealy, one should strive for maximum light but not direct sunlight, early morning and late afternoon sun is fine.
If growing indoors select an area of the house that get good light but not direct sunshine.
In the event that there may be periods of direct sunshine striking the plants at some time during the day shelter them with some form of light shading.
Many bromeliads are epiphytic meaning they need good air movement around them, so good ventilation (but not draughts) is essential.
Bromeliads like the temperatures of around, 21°-24°C (70-75ºF),some can tolerate temperatures down to 10°C (50º.F)
They may require higher temperatures to make them into bloom.
This is a somewhat grey area!
To feed or not to feed that is the question!
In their natural environment bromeliads thrive on small amounts of nourishment received from bird droppings, dust, stray leaves, and the droppings of tiny creatures that live in their cups.
How does one create this environment?
Consensus is a little balanced liquid fertiliser should be given at each watering.
However this has got to be weighed up with the type of plant and the amount of light plants are receiving so perhaps the following is the way to go;
Cupped varieties growing in a glasshouse: give a half strength feed at each watering.
Ditto growing indoors: give a quarter strength feed at each watering.
This dilution is important because if the cups are allowed to dry up before the plant has absorbed the fertilizer it will tend to burn the plant, so err on the side of lower fertiliser strengths.
Similarly, if plants begin to produce leggy growth reduce the feeding strengths or frequency.
Non-cupped varieties growing in compost can be top dressed with slow release fetiliser pellets at the start of the growing season.
All varieties can sprayed with half-strength liquid fertilizer several times in the summer.
Mix the fertilizer with distilled/cooled boiled water, not tap water.
Pests and Diseases:
Bromeliads are relatively pest and disease free.
Occasionaly they may be attacked by scale insects which can be controlled with a suitable soap based insecticide.
Sometimes they can be affected with a fungal disease that is most likely attributed to temperature / humidity control.
This will show up as either black spots or a soft rotting spot sometimes with a yellowing center.
Cut all of the damaged area away with a sharp knife and treat the plant with a suitable fungicide applied to the manufacturers specification.
As most plants grow older, it is quite normal for outer leaves to turn yellow and die, removal will suffice.
They are propagated from vegetative offsets and seeds.
Offsets can appear before the plant blooms but are normally produced after blooming.
These should be be removed when they are one third to one half the size of the parent plant and potted up.
Seeds can be collected from berries or pods which form after flowering.
In the wild seeds are dispersed by the wind
Seeds lose vigour rather quickly so it is advisable to sow immediatly after collecting and sow on the surface of an open moisture retentitive copost then germianate them at a temperature of 27°C (80°F)
Once the seedlings have produced three or four leaves pot them up and leave the pots under a propagator lid to maintain humidity.
When they have grown six or more leaves pot them on again and gradully acclimatise them to room conditons.
Plants grown from seed can take many many years to grow to flowering size so growing from off-sets is the quicker option.