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Easy, captivating, Bromeliads

The flowers of bromeliads, which can bloom at almost any time of year, are usually striking and brilliantly coloured.

The flowers of bromeliads, which can bloom at almost any time of year, are usually striking and brilliantly coloured.

What is the phenomenon of allure and captivation bromeliads exert over people? Maybe it is just the whole fascinating gamut of the bromeliad family. But be warned, the bug will get you once you take one home, they are addictive.

Bromeliads are mainly tropical, rosette‑forming plants that differ from most other flowering plants in that they absorb their food and moisture largely through leaves rather than roots.

Bromeliads (airplants) are members of the family Bromeliaceae. These tropical or subtropical plants vary widely in shape and size. Even species of a single genus often differ drastically in appearance. Most bromeliads cultivated as house plants, however, are alike in being stemless, with strap‑shaped, leathery, arching leaves arranged in a rosette, and with a central flower spike on a relatively long stalk.

The rosette may be just a loose open circle of leaves, or it may be more tube-like. In many bromeliads the leaves sheathe one another to form a cuplike, watertight vessel. In the wild, rainwater and dew collect in the cup, and the plants draw their water and food needs from this reservoir during dry periods. Bromeliads are unique among plants in that they need to have water around the growing point (situated at the centre of the rosette). Water lodging permanently in the heart of any other non‑aquatic plant would eventually kill it.

The majority of bromeliads grown as house plants are epiphytic, living on the trunks and branches of trees. Some attach themselves to rocks. The rest grow in the ground as most plants do. Within the same genus there are sometimes tree‑dwelling, ground-dwelling, and rock‑dwelling species. In fact, epiphytic and terrestrial bromeliads can often thrive equally well if forced to switch places and life styles. It is this ability, in particular, that allows some epiphytic kinds to be grown in pots like most other plants.

Practically all these plants have leaves capable of absorbing airborne plant food in addition to any that may be taken in through the roots. Even the minute scales that cover the leaves of some types are themselves able to take in food materials and moisture. In fact, many bromeliads have entirely ceased to rely on roots for their nourishment. Such plants now either produce no roots or use the few that they do produce as anchorage rather than for feeding.

The flowers of bromeliads, which can bloom at almost any time of year, are usually striking and brilliantly coloured, and they are often partly encased in highly decorative, usually bright red or pink bracts. In some bromeliads the blooms rise barely above the average level of water stored in the cup of the rosette. Individual flowers are rarely bigger than 30cm across, and they appear in succession on a broad, stalkless flower head. The leaves, or portions of leaves, at the rosette centre often become bright‑coloured (usually red or purple) just before and during the flowering period. The brilliant colouring is nature’s way of attracting pollinating insects and birds to the flowers.

Other bromeliads have a different type of floral arrangement consisting of a long, erect and sturdy flower spike that pushes up from the rosette centre.

The spike is topped by a bold, usually brightly coloured flower head bearing flowers that are normally only 25mm across but surrounded by brightly coloured bracts. The leaves do not change their colour during the flowering period.

Flowers of all bromeliads tend to be short‑lived. The bracts of the long-stalked kinds and the striking leaf colouration of the others remain attractive for several weeks, however. Moreover, flowers of some kinds are followed by colourful berries. These normally remain attractive for several months before they shrivel and fall off.

As a rule, each rosette of leaves flowers only once and then slowly dies. The only exceptions among the bromeliads grown as house plants are the dyckias, the rosettes of which continue to grow. In all others the rosette remains attractive for several months before it finally yellows and dries up. Well before this time, however, offsets will have replaced the dying rosette.

Bromeliads flower only when they are mature. It may take as long as 20 years for some kinds to reach maturity. The most popular indoor bromeliads generally flower relatively early, when they are no more than two or three years old.

EPIPHYTIC BROMELIADS

As each young epiphytic bromeliad grows it sends down wiry roots over the surface of the tree, clinging to the bark. The plant lives and grows not only by absorbing water and food from the atmosphere, but also by taking nourishment from any detritus (fallen leaves and other debris) that accumulates between the leaves. The roots of these bromeliads are used for support only.

Epiphytic bromeliads that grow on the lower parts of tree trunks in the wild tend to have soft and pliable leaves. Leaves of species that naturally grow closer to the tops of trees are likely to be harder and more leathery. The difference comes from the degrees of light and shade at different heights within the forest, and this helps to indicate the indoor lighting preferences of plants. Soft, thin‑leaved bromeliads generally do best in bright filtered light, which suggests subdued or dappled light. Brighter light, including some direct sunlight, is better for plants with more leathery leaves.

NON‑EPIPHYTIC BROMELIADS

The bromeliads that grow on the ground or in rock fissures normally live in open, warm, sunny places. Because they grow in exposed positions and are prey to grazing animals, many of them are armed with sharp spines and hooked teeth on the leaf edges. In this respect they resemble cacti and some succulents.

The rosettes are usually far more open and much less capable of storing water than are the rosettes of the epiphytes. Some (certain of the cryptanthuses, for example) have only five or six pointed leaves, which grow in a star shape against the ground. Some do not even have their leaves arranged in rosette shape. Most, though, are quite easily recognizable as bromeliads.

The best‑known non‑epiphytic bromeliad is the edible pineapple (Ananas comosus). It is also the only one grown as a commercial crop.

PROPER CARE

Light As was emphasized above, epiphytic bromeliads need either bright filtered light without direct sunlight or bright light with several hours a day of direct sunlight, depending on the texture of their leaves (future posts that profile individual bromeliads will provide specific recommendations). Terrestrial and rock‑dwelling types generally require the brightest possible light to bring out the best leaf colouration and encourage flowering.

When light intensity is low or day length very short, bromeliads will usually stop growing and take a rest. However, they do not appear to grow as quickly during the long days of intense summer light as they do in spring and fall. There is no cause for concern about fight, therefore, if a plant takes a brief summer rest.

Temperature Normally warm room temperatures are suitable for all bromeliads throughout the year. The thinner‑leaved species in particular will die if exposed to temperatures below about 12oC. Even the few kinds (such as some billbergias) that can tolerate lower winter temperatures, will not react well to a prolonged period below 12oC. Some leaf damage is inevitable after more than a few days of such temperatures.

Along with a fairly constant level of warmth, nearly all of these plants require high humidity when actively growing. Stand pots on trays of moist pebbles. In addition, whenever room temperatures remain above 20oC for more than a day or two, mist‑spray.

Watering In those bromeliads with a central water‑retaining cup, it is essential to keep the cup full of water at all times. To prevent the water in this reservoir from becoming stale, turn the plant upside down once a month, let the old water drain out, and refill the cup. Apart from this process, water the potting mixture for most types of bromeliad moderately, allowing the top 10mm of the mixture to dry out before watering again. During the brief rest period that some plants may take at some time in winter, give such bromeliads only enough water to keep the potting mixture from drying out completely.

In areas where the water is hard, use rainwater as much as possible. Hard water leaves unsightly lime deposits on the foliage. An alternative to rainwater is the melt water that is produced by a defrosting refrigerator. Do not use this soft water while it is still ice‑cold, though. Leave it out in a warm room for 24 hours before applying it to plants.

Feeding Apply fertiliser to actively growing bromeliads according to the specific recommendations which will be included in the plant profiles that will be added to this site. Liquid fertiliser can be poured into either the potting mixture or the cuplike centres of rosettes, or it may be splashed over the leaves. Bromeliads grown in potting mixtures that contain a high proportion of peat moss need to be given some extra nourishment at regular intervals throughout the year. Bromeliads grown in a mixture that is largely soil based should not be fed during any winter rest period that they may take. It is always better to give too little rather than too much of any type of fertiliser to bromeliads

Pests and Diseases Scale is the major pest. A spray with a non-oily scale spray (can cause leaf discolouration in some plants) a couple of times a year will help keep them clean. Never use copper based sprays or white oil or any oil based sprays, as they will kill the bromeliad . Keep the plants clean by pulling the old leaves off the base with a sideways action and this helps keep pests away. In very hot areas during hot humid weather, sometimes the water in the centre of the bromeliad can virtually cook it, the centre of the plant will turn red/pink and if you pull on the leaves the centre will fall out. A fungus causes this and during very hot times they need to be hosed late each day to prevent fungal attacks, however this is very isolated . A spray with Diazanon (Mancozeb) fungicide will prevent and cure the problem if seen early.

A post on propagating and potting bromeliads will follow shortly. A series of Bromeliad plant profiles will be posted over time so visit this site regularly.