How to Grow and Cultivate BROMELIADS

Bromeliad is the word applied to any of the 2000 or so species of plant that comprise the Bromeliaceae family. Perhaps the best known bromeliad is the pineapple, which is native to the West Indies. It is a bromeliad known as far back as the 15th century, and with the onset of widespread exploration it was not long before it was introduced into Great Britain. Its decorative shape gained it a place in the impressive fascias of many large country houses, During the latter part of the 19th century. plant-hunting and botanical expeditions brought back to Britain many other attractive bromeliads. Some of the plants found their way into botanic-gardens. and so initiated a botanical and scientific interest in the Bromeliaceac. From 1830 to 1840 several plants were recorded which are still popular today. such as Aechmea fasctata, Billbergia zcb-rina and Vrlesea splendens. Today, a wide selection of bromeliads is available from specialist nurseries and an increasing number are available from florists. garden centres and large departmental stores.

BROMELIADS IN THE WILD

Bromeliads are native to many locations in the Americas, but as a result of botanical expeditions they may now be seen growing in many different countries. They can be seen in gardens and parks in areas such as Devon and Cornwall. Indeed, in areas of really favoured weather Fascicularia blcolor grows well outdoors.

They occur in their native areas in such contrasting environments, that inevitably there are plants for the home. greenhouse and office. From the humid rain forests of Brazil and Costa-Rica -growing among the large philodendrons and the twining orchids- are to be found a selection of bromeliads ranging from tiny epiphytes nestling in the rough bark of a giant tree to enormous urn-shaped plants 2.1m (7ft) across: these are quite capable of holding at least a litre (1.7 pints) of rainwater.

Across the States of the American Deep South, in areas of the Fverglades and the Okefenokee Swamp, grow a different range of bromeliads. In such places grow the Spanish moss (Tillandsia usneoides)

and the ball moss (Tillandsia recurvata). Grey in appearance, and with little or no root, these epiphytic plants hang from trees, telegraph poles, and even from the wires, existing on the moisture which is present in the atmosphere. These two species grow in such profusion that branches of trees break under their weight. These plants are of little use to the local inhabitants, and have little to offer economically, except perhaps for use as a tilling for upholstery or a binder in the preparation of bricks. In desert areas bromeliads are also in evidence. The savannah of Veracruz and the arid regions of Mexico provide homes for the small, hard, rosettes ofdyckia and hechtia. While from the Argentine come clustering plants of the genus Ab-romietieUa. The Andean mountain range and Peru have the largest brom-elaid – Puya raimondU. This species will outlive most humans, taking what is our average life span before it matures to flowering size, about 10.5m (35ft) high. Using the puyas. large columnar cacti. or rocky outcrops for supports are the xerophytic tillandsias. attaching themselves to their hosts by wire-like roots. A xerophyte is a plant which has adapted to grow in dry conditions.

Rain forest bromeliads Plants native to the rain forests or cloud forests are fortunate, as they luxuriate in what are virtually perfect conditions for their growth – high temperatures and humidity, diffused light and little air movement.

Fvery tree is covered by some form of plant life, be it mosses, lichens, ferns or aeroids. In such an environment, the growing medium is of little importance and bromeliads will be found almost everywhere – on living trees, fallen logs, the forest floor, and even growing upon each other. The urn-shaped forms of vriesea and guzmania sit resplendent in niches formed by large branches, their tangled roots securing them to the bark. Decaying logs, adorned with multi-hued fungi, provide platforms on which sit the glossy-leaved nidulariums and neoreg-elias. The moss-covered remains of tree stumps make a fitting green backcloth to the many varied forms of earth stars (cryptanthus).

Intermediate bromeliads

If it were possible to have an escalator in the rain forest and to proceed to a higher level, the changes in the plant life would be quite noticeable.

On such a level, termed an intermediate area, the intensity of light and the amount of air movement increase, humidity is less, and the temperature fluctuates. The climate of such an area is similar to that of an average English summer.

These tougher conditions mean that the plants, too. must toughen up to survive. There the bromeliads exist as epiphytes. alongside orchid cacti, zygocactus and rhipsalis. The roots of such bromeliads are harder and stronger than those produced by the plants at lower levels. and they form a strong anchorage to the trees. No form of nutrition is gained by the plants from this union. Instead, they have evolved a method by which they collect what nutriment is required. The rosettes of leaves form tight, upright vases. These vases retain rainwater. insects and leaf debris which fall into them. Small birds perching on the plants add their own form of manure and the whole concoction forms an excellent brew on which the plants exist. The thick leaves are scruffy, spitefully spined along their edges, and the brighter greens of the rain forest bromeliads have been replaced with a mixture of dark greens, greys, browns and purples. exotically striped or mottled with lighter colours.

Other bromeliads in these intermediate areas are bulbous shaped, with tapering. tendril-like leaves which are channelled to guide the droplets of moisture to the centre of the plant.

Desert bromeliads

Bromeliads have even adapted to the rigour of the deserts. The types to be found there are in the form of low-growing rosettes of hard, dark-green leaves, or grey tomentose. The leaves are edged with spines.

Their way of life is terrestrial, absorbing small amounts of moisture and mineral salts through a normal root-system. In

an attempt to avoid strong sunlight, the plants have drawn themselves down into the dusty terrain. Alternatively, in the case of the more fortunate ones, they manage to grow in the shade of larger plants or grasses.

BROMEUADS AS HOUSEPLANTS

The sheer range of shape and form make bromeliads interesting plants for the home. There are many different types of rosettes – in most cases stemless – and they range in size from minute plants 12mm or so in diameter to species far too large for the home. The forms of leaf vary immensely. Simple strap-shaped types are displayed by vrieseas or guzmanias, while billber-gias have still’, upright vases. The genus cryptanthus has flat, crinkly leaves, and acanthostachys has leaves of a hard. pendent form, reaching 60cm (2ft) in length. In the genus neoregelia can be found a variation from hard-leaved vases to flat rosettes of leaves, softer in texture.

The tillandsia have such a large assortment of types that a collection of this genus alone warrants an interest. There are large plants with thin, strap-shaped leaves (P. lindenii). bulbous species with rolled leaves (P. butzii), tufted plants which resemble silver grasses. spiral-shaped types which are powdery in appearance (T. balbisiana),

and octopus-like forms which glisten with a covering of scales (’P. seleriana). Plants dependent on an epiphytic way of life rely on a covering of specialized organs called trichomes. These are absorptive organs acting in a way similar to minute sponges – absorbing atmospheric moisture. Although most bromeliads possess trichomes, they are found in higher concentrations in xcrophylic types of tillandsia.

The leaf coloration in bromeliads is interesting. In the billbergias there is a chocolate and grey combination (Billbergia zebrina), yellow and grey dappling (B. ‘Fantasia’), green with while (B. por-tecma), and olive to purple (B. vittata). As its name implies. Vriesea bleroglyphlca has dark figurations on a light green background, and V. gigantea (syn. V. tesselata) appears translucent when the light Biters through its leaves. Aechmea chantinii has silver striping on a darker base colour, while A. orlandiana is a mixture of green, brown and purple. The many forms of cryptanthus have a tendency to hybridize easily, giving an unbelievable mixture of multi-coloured variants and the pinkish tinge on a cream-and-green combination makes the variegated form of Ananas bracteatus a favourite of many people. The flowers of bromeliads range from the insignificant to the breathtaking – even in different species of the same genus a

contrast can be found. In Tillandsia iisiieoides the flowers are small, yellow tinged white and will go unnoticed unless the plant is viewed closely. However. T. cyanea has a most colourful purple and pink inflorescence. Dyckias produce their orange flowers on stalks, but the small, white flowers of cryptanthus are almost hidden. Sadly, the red to pink and blue flowers of the billbergias are short lived. On the other hand, the aechmeas produce long-lasting blooms from the dark purple flowers pendent on a carmine stalk as with A. fuhiens. to the pyramid-shaped pink-and-blue inflorescence of the distinctive and attractive A. fasciata. Neoregelias and nidulariums are termed nest plants, as the tiny blue to mauve flowers sit nestled in the central cup. In some species, such as Neoregelia cawlinac ‘Tricolor’, the central area of leaves Hush a striking scarlet as a prelude to flowering. In contrast, the vrieseas gain the epithet flaming sword plants, referring to the 60cm (2ft) lance-shaped inflorescence of red bracts and yellow flowers. In the genus of the soft-leaved guzmanias. the dominant colour of the flowers is while, but the contrasting colouring of the bracts – yellow, green and orange – make these plants an asset to any collection.

It is the varied nature of these plants that makes them so interesting.

Good plants to grow Only a fraction of the bromeliads discovered are grown by plant enthusiasts. This is because many natural environmental conditions cannot be reproduced. Some plants natural conditions are too demanding, but fortunately these are in the minority. With the ones which are readily available it is not difficult to assemble a good, representative collection of easy culture. Then, if the interest in the group matures, specialist nurseries have less common species. The following list comprises plants that are obtainable without too much effort -and they will provide an assortment of attractive leaf types and flowers. Plants from the rain forests: Aechmea chantinii, A. ‘Foster’s Favorite’, A. ful-cens. A. orlandiana. Ananas sugenaria ‘Striatus’ (syn. A. bracteatus ‘Striatus’).

A. comosus ‘Variegalus’. Cryptantbus be-

uckeri. C. bromelioides ‘Tricolor’. C. fos-

terianus, C. zonatus, Guzmaina lingulata,

G. lindenii, G. minor. G. musaica. G.

monostachya, G. zahnii, Vriesea carinata.

Plants from intermediate areas: Aechmea

coelestis, A. fasciata. Billbergia ‘fantasia’.

B. nutans, tt. porteana, li. windii. B.

zebrina, Cryptanthus acaulis, C. bivittatus,

Neoregetia ampuUacea, N. spectabilis, T.

Uislis, Tillandsia bulbosa, T. butzii, T.

caput-medusae, T. recurvata, T. usneoides.

Plants from desert areas: Dyckia brcvi-

folia. Tillandsia baileyi, T. ionantha.

CULTIVATION

The cultivation of bromeliads is no more difficult than any other group of plants. and in some ways they are far easier. As with all plants, some consideration should be given to the conditions required by the bromeliads. Prime importance is to treat each plant as an individual. and not to classify a complete genus as requiring one specific treatment. l;or instance. Vriesea splendens is a shade lover, yet V. espinosae, looking like a tillandsia, favours good light. Selected types can be grown to match the conditions available or the types can be mixed, varying their position. This method can be seen to advantage in the bromeliad collection at Kew Gardens. London. There, the plants are grown in a natural setting, some in shade, others in a brighter position, with a ’cw epiphytes on the lower portions of cork-bark ‘trees’, others perched high up. In this way. a natural balance is achieved which is pleasing to the eye and beneficial to the plants.

Growing media

Most of the forest bromeliads grow as epiphytes with the minimum of material around their roots. Therefore, whatever medium is used it must be open, with good aeration and ample drainage. A soil-mix used for most pot plants is not suitable, as it will cloy and sour the plant. A base mixture of peat should be

employed, with an addition of some granulated charcoal. This can be opened up by using sphagnum moss, osmunda fibre, pine tree needles, or the expanded larva products as used for hydroponics, in a one-to-one ratio. A point to note when potting the plants, is that they need to be planted firmly; if the compost is suitably moist when potting, it can be firmed around the plant. Species from the deserts will fare well if grown in a mix of equal parts loam, sand and peat.

The xerophytic tillandsias are not suited to pot culture and are best attached to rough-barked branches such as elder. cactus skeletal wood, or cork bark. They can be positioned with the minimum of sphagnum or osmunda placed around the roots, and then secured with plastic-covered garden wire. After a kw months of growth, the plants will produce new anchorage roots which will embed themselves into the wood.

Light

Light is one of the most important aspects of bromeliad culture, as the amount and intensity given to the plants has a great effect on their appearance. The soft-leaved plants from the rain forest prefer semi-shade, and too bright illumination will cause burning of the leaf tips and edges. Plants from the other areas require good light, with some sunshine. This light helps to retain the

striping and variegation which, in shadier conditions, would be lost, so taking away some of the natural beauty of the plants. The desert-growing genera and the small, grey tomentose epiphytes enjoy good light intensity, with sunshine, preferably in a south-facing window. To make the plants really feel at home, some form of artificial lighting can be employed for a few hours during the short days of winter.

Watering

The amount of water required will depend on the type of plant. Those from rain forests should never be allowed to become dry. Spraying the plants daily with a line mist helps to maintain a good level of humidity, without the plants becoming excessively wet around the roots.

Plants with a harder leaf texture should be allowed short periods of dryness. Those with a central vase can be tilled with a small amount of water, except when it becomes obvious that a flower bud is imminent or that the flower may become infected by mildew. Naturally, the genera from a desert environment require less moisture – a weekly watering in spring and summer. reducing the amount in autumn and winter, depending on the temperature of the room in which the plants are grown. With tillandsias mounted on wood, misting is sufficient, the frequency being varied according to the season. During the period of rapid growth, misting In the morning and evening is favoured. However. in the cooler months, once or twice a week will suffice. A dry area plant will never be lost through being under-watered. In fact, all of the bromeliads can safely be left for two or three weeks. Where possible, rainwater should be used, as in some areas the tap water can be rather alkaline and this tends to leave a residue on the leaves, making them unsightly.

Temperature

fortunately – in these days of high fuel costs – bromeliads are very adaptable with regard to the degree of heat they require. In the home, where heating is available, no further allowances need be made for the plants. The most demanding plants are those from the rain forests, preferring 18 deg C (65 deg F)as a minimum. Those types with a harder leaf texture are less particular. and if something like L0 deg C (50 deg F) can be maintained they will grow quite well. If. in an emergency, the temperature drops slightly, the plants should come to no harm, especially if the soil is kepi rather dry. Fascicularia bicolor, a native

of Chile, is hardy and can be grown as a garden plant in a sunny position-on the rockery or in a large tub on the patio where, even when covered with snow, it should survive.

Feeding

As with the majority of houseplants. the amount of growing medium contained in the pots has limited capabilities over a lengthy period. With bromeliads. where maturing takes some years, it is advisable to administer some form of fertilizer, particularly where it is evident that a plant is approaching flowering. A good proprietary brand of an organic feed can be used.

With the vase types and earth stars, dosage and concentration can be as recommended for pot plants, and given during their active period of growth. Additionally, a dilute solution – one-third of the concentration -can be added to the water in the central cups occasionally.

Feeding of the desert varieties is less advisable, but can be done once or twice during the period of active growth. Although the air plants tillandsias appear to receive no nutrition in nature,

they usually have a covering of dust particles which provide some food. Dilute manuring in the warmer part of the year will be appreciated.

Pests and diseases

In their natural habitat, the bromeliads fall prey to many setbacks. However, under cultivation the situation is easier. Two types of pest that may be encountered are those prominent in attacking cacti and succulent plants, namely mealy bugs and scale insects. The mealy bugs generally infest the more tomentose plants where they can go undetected in the axils of the leaves. Scale can be a problem with the larger plants, such as the neoregelias and aechmeas.

Chemical controls are available but it should be remembered that the plants absorb moisture through the leaves, and care must be taken in treating the problem. If possible, a more personal touch should be given. Both of these pests can be removed from the plants, using a cocktail stick tipped with cotton-wool soaked in methylated spirit. The removal of the scale insects should be done with

care on the plants that have a powdery bloom to the leaves, as this is easily removed, making the plants unsightly. House spiders, while not being classed as horticultural pests, can be a nuisance, as they tend to make webs across the central cups of the larger plants. All that is required here is to remove them bodily.

Horticultural diseases that affect the Bromeliaceae are few. A fungal disease can attack plants of aechmea when grown in a commercial quantity in nurseries, but will not be found in small collections.

One problem that might arise will be with the neoregelias and nidulariums. After flowering, the remains in thecentral cups might develop to the fruiting stage and if too moist will be susceptible to fungal attack. Remedial steps involve removing the remains and flushing out the cups with methylated spirit before rinsing thoroughly with clean water. Generally, however, problems are few.

PROPAGATION

Bromeliads can be propagated from offsets or seed. Offsets produce flowering plants more quickly, but seed offers the possibility of more plants. Seed. Seeing a plant in flower may give you the inspiration needed to try producing plants from seed. Some species, such as Vtiesea splendens, are self-fertile. but in those plants which are not, pollination can be induced. In the case of the billbergias, pollination must be effected quickly due to the short life of the flowers. Then, again, there are those species whose flowers open only at night. Temperature is another aspect that will affect pollination. In some cases, the seed is set by the aid of insects. When the fruits have been formed they can be collected and the seeds squeezed out. They can be rinsed in a mild disinfectant. teased out and dried. The seed of most genera will remain viable for several months, after which germination may be retarded. The variation in the shape of the seeds is extensive, from the flat forms produced by dyckia. the thin seeds of pitcairnia to the small parachutes of tillandsia and vriesea.

The compost used for germination should be line, without any lumps or large granules, and have a buoyant consistency. Sieved peat is a good choice. with some finely-chopped sphagnum moss added. The inclusion of some granules of charcoal helps to keep the mix sweet. It is preferable to well moisten the mix before adding it to the trays. rather than water after sowing, which could mean that the seeds float together on the surface.

Another method utilizes synthetic sponges that are used about the house. The sponge is soaked thoroughly and the excess water allowed to drain off. The seed is sprinkled on the sponge and enclosed in a polythene bag. After germination, the sponge can be sliced into portions containing a number of seedlings and these portions placed into a compost. Some of the small tillandsias will germinate quite well on bundles of pine needles, on blotting paper, or most materials that have a good moisture content.

As with most seeds, the temperature for germination must be high. 21°-24 deg C (70 °-75 deg F). The seed-trays should be covered with glass sheets and if bottom heat is available, so much the better. Depending on the species sown, germination should be completed in six to ten days. When the seedlings are evident, it is wise to cover the glass lids with paper to reduce the light and deter the algal growth that can be a problem.

A close watch should be kept on the moisture of the compost, as drying out at this time could be fatal for the seedlings. As the growth progresses, the seedlings can be allowed to have stronger light intensity, with the removal of the glass covers to give good air circulation. Again, avoid any drying out. When the seedlings have reached 2.5cm (1 in) or so in height, they can be transferred into smaller communities, given more air and perhaps a spray of fungicide to prevent damping off. As the growth progresses, dilute fertilizer can be applied. Later, when it is noticeable that the characteristics of the plants are established, they can be potted into a particular compost. Specialized treatment with regard to light and water can then be given. Seed of some species can be bought from seedsmen specializing in uncommon plants.

Offsets. The time taken for the different genera of bromeliads to mature to flowering size varies depending on the species and the cultural conditions the plants receive.

Some plants, cryptanthus for example. will mature in three years. Larger growers, like aechmeas and vrieseas. can take something like live years, and slower-growing genera may not mature for seven years or more. The propagation of plants vegetativcly by offsets or cuttings means that it is possible to have mature plants earlier than by seed, showing their natural characteristics and colourings earlier. Another point is that to obtain a true-to-type plant, such as the man-made Cnjp-tanthus It Neoregelia ‘Red of Rio’, and Vriesea ‘Mariac’, vegetative propagation is more reliable than seed, since in some cases the flowers are sterile and produce no seed. This accounts for the high prices demanded for these cultivars. The bromeliads are monocarpic. this means that each plant will produce flowers and then die. As with the houscleeks of our rockeries, offsets are produced either singly or in profusion. while the adult gradually dies away during the following months. Obviously it is not necessary to remove offsets from the parent plant, unless for commercial interest or exchange, for nothing looks better than a clump of four or five plants emanating from the same rootstock, particularly when all the heads are in flower together. It is fortunate that most of the bromeliads are on the fleshy side or else xerophytic, so that there is no fear of the offsets drying out between the time that they are taken and the time that they are rooted. With this prospect in mind, it

means that it is possible to have cuttings sent from other parts of the globe, without any fear that the plants will succumb should there be any undue delay in the mail.

The best time to root the offsets is obviously in the period of rapid growth. spring to summer. However, any time will be suitable if the room is heated. If the container of offsets is placed on a radiator, to provide bottom heat, rooting will be hastened. The peat and sphagnum mix used for seed germination will also be suitable for rooting offsets, or mica-flake products can be used. The methods of offset removal are different from one genus to another. In the genus Cryptanthus, the small plants will appear around the centre of the mature rosette: they are very delicately attached and are removed easily, even accidentally. If one batch of offsets is removed. the plants will produce more. The genus Billbenjia has species that produce young plants on stolons, a hard form of stem that radiates from the parent plant, usually hanging over the side of the plant pot. I [ere, a sharp downward snap gives a clean break. In plants of the genus Aechmea, the young shoots are produced closer to the parent plant, and it will be wiser to let the shoots attain some length before separating them. Removing the plant from its pot will give easier access. The harder-leaved neoregelia produce stolons or runners, but the soft-leaved types and the nidulariums complicate matters somewhat as their offsets grow nearer to the centre of the plant. It will be easier to allow some of the leaves of the old plant to die away before making any attempt at removing the offsets, by which time they will be a better size and more conveniently handled. The problem created by the vrieseas is that the new shoot, unfortunately just the one. appears between the leaves of the old plant, thus it is just as well to leave it on the original rootstock. The best method to gain an increased number of plants of this genus is by seed. The genera Cryptbergia and Fascicularia are so prolific that they require nothing more than splitting up the clump to gain complete plants.

With tillandsias propagation could not be easier, since they can exist for months without roots. Offsets are wrapped in moss and wired on to the chosen position on the branch. With T. usneoides, nothing more is required than to pull off a few strands and to hang them somewhere.

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