Dendrobium - Orchids - Cultivation techniques and main species of the Dendrobium orchid


OUR ORCHIDS FRIENDS

DENDROBIUM

Cultivation techniques

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BOTANICAL CLASSIFICATION

Kingdom

:

Plantae

Clado

: Angiosperms

Clado

: Monocotyledons

Order

:

Asparagales

Family

:

Orchidaceae

Kind

:

Dendrobium

Species

: see page 2

GENERAL CHARACTERISTICS

To the genre Dendrobium belong species native to all of eastern Asia, from the Pacific to the Himalayas, Australia and New Zealand.

It is certainly one of the most numerous genera of the orchid family, including more than 900 species living in very different habitats: at sea level and up to 3500 m of altitude, some in temperate climate regions, others where temperature and humidity are located. it is constant throughout the year, others in tropical climates. This fact means that you have Dendrobium with very different cultural needs, shapes and sizes: we have Dendrobium very small in size of 3-4 cm e Dendrobium very large, several meters long with the most diverse shapes and colors that make this species unique and irreplaceable for orchid lovers.

All this is complicated by the fact that there are many hybrids on the market and consequently many types of Dendrobium.

Their name derives from the Greek dendron "Trunk, tree" e bios "Life" to mean the fact that they are orchids EPIPHITEbut there are also species with behavior

LITHOPHYT and even some TERRESTRIAL.

The morphology between the Dendrobium is very different from each other, we find in fact species with evergreen leaves and others with deciduous leaves, some with single leaves, others gathered in groups.

One characteristic that the different groups have in common is that of forming godskeiki (photo on the side) both at the height of the nodes and at the base of the stem which are nothing more than a new orchid seedling which, once sufficiently large, can be detached from the mother plant and be repotted autonomously.

Very often we hear: «forget about the Dendrobium because they are very difficult to cultivate ». Personally I do not agree with this statement because, even if it is true that it is essential for this genus to know the species it belongs to in order to frame its cultural needs and often some require extreme conditions that we are very difficult to reproduce in our homes, it is also true that since there are about 900 species, we can easily find the ones that can best adapt to the climatic conditions closest to us.

In general, to understand how to breed i Dendrobium we keep in mind that they are plants that have a very rapid vegetative period, that is to say they develop the green parts and the roots very quickly, but instead take much more time for flowering and the production of seeds. This situation is dictated by the fact that vegetative rest corresponds in nature with the seasons less favorable to their development, that is to say cold and dry, conditions in which the plant could not survive if not precisely entering into rest and using during this period the reserves stored in the pseudobulbs during the stage of full development. In nature this unfavorable period is longer than the favorable periods, for this reason they have this particular cycle.

Considering that they are plants with the most diverse habitats, it is impossible to generalize their cultivation techniques. For this reason some divide i Dendrobiumin six groups and for each one the typical cultivation environments are described.

In this group, i Dendrobium deciduous and cold ground which need a period of vegetative rest.

We find the following species:

  1. Dendrobium nobile;
  2. Dendrobium chrysanthum;
  3. Dendrobium wardianum;
  4. Dendrobium victoriae reginae.

Here we find the Dendrobium nobile, certainly the most famous among the species of this group.

They are all plants native to Southeast Asia including Nepal, Bhutan, North East India, Burma, Vietman, Laos and part of South East China, at altitudes between 200 - 1500 m.

This group, as well as the second, has the particularity of losing its leaves during the dry and low temperature period which in nature coincides with winter. In fact, in this period, as there is not enough water and temperatures to grow, the plant enters vegetative rest, loses its leaves and therefore saves its nutritional reserves and lives with the reserves accumulated in the pseudobulbs. With the arrival of heat and rain, it restores its reserves very quickly and prepares for reproduction, that is, for flowering and for the production of the seed (let's not forget that plants bloom for the propagation of the species).

In addition to these species there are also numerous hybrids obtained above all by crossing them Dendrobium nobile x Phalenopsis or Dendrobium nobilex Dendrobium bigibbum.

For these orchids the cultivation cycle is particular and is also valid for the hybrid derivatives.

From mid-autumn (November) to mid-winter (February)they must be kept as cold greenhouse plants with temperatures around 10 ° C, in a very bright place (in their natural environments the light is much more intense in winter than in summer) and giving very little water, just enough not to make it wither, no fertilization and excellent ventilation. For the quantity of water to be given, it can be adjusted by observing the stems: if we see that they begin to shrivel, we need a little water, but very little. The lower the temperature, the lower the water must be.

As soon as flower buds are formed, which generally coincides with spring, you can do some watering until the end of flowering.When even the last flower has fallen, suspend irrigation again until the roots begin to emerge from the new shoots. At that point the plant must be brought back to an area with higher temperatures and resume irrigating and fertilizing regularly. During this time they can also be taken outdoors, during which time the light should not be too intense.

Throughout spring and until mid-summer (August) the fertilizations must have a high rate of nitrogen in the dose of 1/2 gr / l once a week.

After that from mid-summer (August) and until autumn continue with fertilizers with a very low nitrogen content and a high content of phosphorus and potassium in the dose of 1/2 gr / l once a week.

This alternation of dry and cold periods with normal and warm periods is crucial for flowering. In fact, the primary cause of the non-flowering of this group of orchids is precisely the lack of this alternation. In its stead the plant will produce gods keiki which are nothing more than new seedlings which, once sufficiently large, can be detached from the mother plant and repotted autonomously.

In summary, to successfully cultivate i Dendrobiumof this group and their hybrids, two basic requirements are needed: in spring-summer very hot, many fertilizations, constant humidity and not too intense light which follows immediately after a cold, dry period, no fertilizations and a lot of light until the flowering which will take place at the end of winter - early spring.

The Dendrobium can stand quietly outdoors during the summer but it must be used very gradually in fact it tolerates the direct sun once developed outdoors if it is acclimatized early in spring and if the ventilation is excellent.

Regarding humidityduring the summer it must be high, around 80% which is gradually reduced as winter approaches 60% until it is completely suspended in winter.

For what concern repottingit can be done either when new roots begin to develop or immediately after flowering.

In this group, i Dendrobium deciduous and intermediate seedlings that need a period of vegetative rest.

  1. Dendrobium anosmum;
  2. Dendrobium findlayanum;
  3. Dendrobium pierardii;
  4. Dendrobium parishii;
  5. Dendrobium heterocarpum;
  6. Dendrobium aggregatum.

This group, as well as the first, has the particularity of losing its leaves during the dry and low-temperature period which in nature coincides with winter. In fact, in this period, as there is insufficient water and temperatures to grow, the plant enters vegetative rest, loses its leaves and therefore saves its nutritional reserves and lives with the reserves accumulated in the pseudobulbs. With the arrival of heat and rain it very quickly restores its reserves and prepares for reproduction, that is, for flowering and for the production of the seed (let's not forget that plants bloom for the propagation of the species).

The species belonging to this group are bred like those of the first group with the only difference that the temperatures are constant throughout the year. At night around 12-14 ° C.

Vegetative rest must be ensured starting from autumn and throughout winter, when the irrigations will be gradually reduced and at the end water will be watered enough not to let it wither and the fertilizations will be completely suspended. When the flower buds start to appear and are well developed, which coincides with the spring, gradually resume irrigation until you see that the plant has fully awakened producing new roots at which point you can resume watering regularly and also fertilizing. During this period, spring and summer, they need a lot of light and a lot of air.

Vegetative rest is essential to have flower induction.

In this group, i Dendrobiumevergreen and intermediate greenhouses that do not need a rest period but must feel the change of season.

We find the following species:

  1. Dendrobium chrysotoxum;
  2. Dendrobium densiflorum;
  3. Dendrobium fimbriatum;
  4. Dendrobium moschatum;
  5. Dendrobium thyrsiflorum;
  6. Dendrobium farmeri.

These Dendrobium, unlike those belonging to the other two groups, they must not be left dry at any time of the year.

During autumn and winter the irrigations must be reduced but not suspended and must be placed in a cool place with night temperatures around 10-12 ° C.

In spring the irrigations are gradually increased and generously fertilized and the plants move to warmer and brighter environments and can be easily grown like Cattleya.

In this group, i Dendrobiumevergreen and intermediate greenhouses that need a short rest period.

We find the following species:

  1. Dendrobium daerei;
  2. Dendrobium loddigesii;
  3. Dendrobium infundibulum;
  4. Dendrobium sanderae;
  5. Dendrobium formosum;
  6. Dendrobium lyonii;
  7. Dendrobium macrophyllum;
  8. Dendrobium schuetzei.

For these Dendrobium the winter night temperatures are around 12 ° C while in summer the night temperatures must be around 15-16 ° C. They cannot bear temperatures that are too high or too low.

Also for this group of Dendrobium, a period of rest of about three weeks must be foreseen with very little watering and no fertilization.As the new shoots begin to form, watering and fertilization are gradually resumed, remembering to always let the substrate dry between one watering and another.

In this group, i Dendrobiumevergreen and intermediate greenhouse without period of vegetative rest.

We find the following species:

  1. Dendrobium stratootes;
  2. Dendroblum taurinum;
  3. Dendrobium undulatum;
  4. Dendrobium veratrifolium;
  5. Dendrobium gouldii.

Orchids belonging to this group do not like extreme conditions as they degrade temperature and humidity that are not too high. They need lots of light and good ventilation. Watering and fertilizing must be regular throughout the year, at least they are slightly reduced during the winter.

If in these circumstances the buds do not bloom or fall prematurely, it is necessary to better regulate the night temperature by increasing it slightly.

In this group, i Dendrobiumevergreen and warm greenhouse without vegetative rest.

We find the following species:

  1. Dendrobium phalaenopsi(also known as Cooktown orchidas found near Cooktown in Queensland - Australia);
  2. Dendrobium superbiens;
  3. Dendrobium biggibum.

This group includes very popular orchids in fact on the market there are many hybrids especially of Dendrobium Phalaenopsis and of Dendrobiumbiggibum.

They are plants native to the tropical areas of south-east Australia therefore they are plants that come from areas where the summers are hot, very humid and wet while the winters are rather dry. This classification is important to understand how to breed them. In fact they are hot greenhouse plants.

First you must keep in mind that they do not go into vegetative rest therefore they must be watered throughout the year.

In spring - summer, which coincides with the growth phase, they will activate generously watering and should be fertilized regularly using 1/2 gr / l once a week with a high nitrogen content. Night temperatures in the summer should be around 22-25 ° C and in the daytime 28-30 ° C. In this period they should be sprayed regularly to try to keep a humidity level of around 60-70%. During the summer they can be exposed to direct sunlight only in the early morning but screened for the rest of the day.

After flowering, watering should be reduced until the new flower stems are formed.

From the end of summer and until autumn, a fertilizer with a higher title of phosphorus and potassium is used, always at a dose of 1/2 gr / l once a week.

From autumn and winter watering must be gradually reduced, leaving the substratum to almost dry out between one watering and another. It is necessary to be very careful not to let the pseudobulbs shrink too much as the subsequent recovery is quite slow. During this period the fertilizations will be suspended or at least significantly reduced in concomitance with the reduction of irrigations. The nebulisations must be done in such a way as to keep the relative humidity around 60-70%. In their natural environments the light is much more intense in winter than in summer so make sure that during the winter season they can get much more light than in summer. Temperatures in winter around 12-14 ° C at night and 15-18 ° C in daytime.

Throughout the year it is important to ensure excellent ventilation.

Repotting it takes place after flowering or when the plant begins vegetative growth at the end of winter-early spring. Being epiphytic plants, they can easily be grown on cork bark. Obviously in these conditions the watering and nebulization must be daily, especially in summer. If grown in pots, you need to be careful to use small pots in fact they do not like large pots. Those that may appear too small for the plant are usually fine. It is also important that they have an adequate number of drainage holes as they do not like water stagnation in any way. As a substrate, cork and fir bark pieces are fine. Repotting is usually done when the plants have outgrown the pot. If you decide to divide the plant, remember to leave at least three pseudobulbs per plant.

In almost all Dendrobium belonging to this genus, the flowers appear in the terminal part of the flower stem in a variable number from 5 to 20 and last from one to three months.

Once the flowers have dried it is preferable not to cut the stem but to let it dry naturally. In fact, from that stem, new lateral branches can be born, or it can flourish again, or a keiki can be born which is nothing more than a new plant which, once sufficiently large, can be detached from the mother plant and be repotted autonomously.

There are cultural differences within the group between the Dendrobium phalaenopsisand the Dendrobium bigibbum, which are often considered a single species even if they are not. The Dendrobium bigibbum it is native to areas much closer to the equator and therefore requires higher temperatures than the Dendrobiumphalaenopsis, especially in winter. Also morphologically they are different from each other: the Dendrobium bigibbum has smaller flowers and a larger and more rounded lip than the Dendrobium phalaenopsis.

GENERAL INFORMATION

WATERING AND HUMIDITY

It is necessary to water in the morning, to allow the leaves to dry before the arrival of the night and thus avoid the onset of dangerous diseases. Care must be taken that the water does not stagnate between the interstices of the leaves.

Maintaining a humid environment around the plant is essential. Now, in our homes it is not always easy to simulate a corner of a tropical forest. To be able to approach this we can place the pot that contains the plant on a saucer (or other vessel) in which you will have placed some expanded clay or gravel in which you will always keep a little water. In this way the roots of the Orchid will not come into contact with the water which evaporating will guarantee a humid environment around it, as well as spraying the leaves once a day.


Keep in mind that the optimal humidity is different depending on the species and also in proportion to the temperature: high temperatures will require greater humidity but in this case it is essential to guarantee the plant good ventilation to avoid dangerous water stagnation that could cause the onset of dangerous pathologies.

It is a good idea, for the health of all our plants, to equip the radiators with a humidifier so as not to allow the air in the room to become too dry.

(For more information on orchid watering see the article: "Orchid watering and humidity").

FERTILIZATION

Like all orchids since they are mostly found on an inert material, the nutritional elements must be provided with fertilization.

Fertilizers must be dissolved in irrigation water, possibly not tap water.

Wet the substrate well before proceeding with fertilization to avoid excessive salt concentration.

(For more information on orchid fertilization you can consult the article: «> Orchid fertilization»).

TYPE OF SOIL - REPOT

Before repotting, the Orchid should be thoroughly wetted to make the roots more elastic and thus avoid breakage. The roots must be cleaned of all the material that remains attached to them and the dead ones must be removed with blades or shears that you have first disinfected well with alcohol or bleach, better seal the flame.

Proceed with great caution and try to disturb the roots as little as possible and be careful to eliminate only the dead ones. Each cutting surface must be treated with broad spectrum fungicidal powders that you will find from a good nurseryman.

Before repotting, wash the substrate thoroughly by leaving it immersed for a few days in water in order to eliminate the dust present, remove the impurities present that end up on the bottom of the container and thus ensure their perfect hydration.

If the roots adhere too strongly to the pot at the time of flaring, it is advisable to immerse the pot for about 30 minutes in just warm water. If this technique doesn't work, then cut the pot. Do not force the roots which could be damaged.

Make sure there is some space between the edges of the pot and the roots to prevent the same situation from happening again the following year.

Always make sure that the container you have chosen has an adequate number of drainage holes (otherwise equip yourself with suitable tools to increase them).

After the Orchid is repotted, leave it dry and away from direct light and temperature changes for several days to allow the cut parts to heal and the roots to adapt to the new situation. Once the root activity has resumed, resume normal cultivation.

As for the type of container, choose the one you prefer (there are the most varied and here your imagination is the master) and if you have chosen a certain size, well, buy it smaller. It is important that the container has been previously disinfected either with alcohol or bleach. It would also be advisable that, if you do not use gloves, your hands are also well cleaned before proceeding.

(For more information on orchid repotting see the article: "Type of substrate and repotting of orchids»).

PARASITES AND DISEASES

As for the diseases of the Dendrobium see the chapter: "Diseases and treatments of orchids".

CURIOSITY'

The name Dendrobium it was assigned by Olaf Swartz in 1799 who at the time counted only 19 species in this genus.

A historical breeder of Dendrobium nobile is Jiro Yamamoto a Japanese who works in Hawaii with the famous Yamamoto hybrids appreciated for the stupendous colors of their flowers.

The Dendrobium phalenopsis o Orchid of Cooktown has been the floral emblem of Queensland (Australia) since 1959 and was included in the 25 cent Australia postage stamp issued on 10 July 1968, designed by R. and P. Warner and in the $ 1.20 one, again Australian designed by Cathleen Cram with illustrations by artist Clare Kaegi.

That the Dendrobium is one of the best known and most appreciated orchids in the country also shows the fact that ... well look what a nice goldsmith has made.

LANGUAGE OF FLOWERS AND PLANTS

See: «Orchids - The language of flowers and plants».

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Dendrobium orchids

- Dendrobium orchid flower "> Dendrobium orchids

Over a thousand species of plants, therefore, which live in markedly different environments, we find some at 3500 m above sea level but also others at sea level, some live in temperate climates others in tropical climates. In addition, there are many hybrids, therefore the various types of Orchids often have an extremely different appearance: some are very small, others very high, the colors are varied and their shape takes on different particularities according to the kind of Orchid we are facing. Some have deciduous leaves, others have evergreen leaves, some species have single leaves and others grouped leaves. But there are two characteristics that all Dendrobrium Orchids have in common. The first is the common idea that an orchid plant is difficult to cultivate and maintain, an idea, however, not always completely true as it is certain that some species are more delicate and need, to live, climatic conditions that we can hardly manage. to recreate at home, but nevertheless, there are many orchids that easily adapt to living in closed environments like our apartments and that do not need special care, except those that must be dedicated to any plant. The second characteristic that unites all the Dendrobrium Orchids is that they all form keiki at the height of the nodes or at the base of the stem, that is, small orchid seedlings that can be detached and planted independently. Furthermore, it is important to know, in order to be able to cultivate and maintain them easily, that many species of Orchids have a fast vegetative period: the roots and the green parts develop quickly, while the production of seeds and flowers is slower. In the cold seasons they have vegetative rest, during this period they do not bloom and use the reserves accumulated in the periods of development to allow themselves to survive in climatic situations that are unfavorable to them.


Commercial hybrids of Dendrobium

Although this is a genre among the richest in species, and also one of the most diverse, the species used for industrially grown hybrids are only the Dendrobium bigibbum and the Dendrobium nobile and a few other related species with which they have been crossed.

The hybrids of Dendrobium bigibbum, also known by the synonym of Dendrobium phalaenopsis , are currently the best-selling orchids as a cut flower, they are much cultivated in the Far East and especially in Thailand, where there are countless cultivations of these orchids exported and sold all over the world.

The elegance of the flowers, the remarkable durability and also the low price have made it successful: we are used a lot, especially as a cut flower in cemeteries. In recent years, the flowering plant has also created its own niche in the market, the size of the plants varies from hybrids even more than 1 meter tall up to dwarf types 20 centimeters high. Dendrobium bigibbum, native to Australia, is a warm and good plant.


Dendrobium aphyllum, also known as Dendrobium pierardii, is a fantastic species, very famous for its blooms. It comes from Burma, Thailand, Malaysia, Laos, Bangladesh, Sumatra, India and China. It grows as an epiphyte (more rarely as a lithophyte on rocks) in the woods at an altitude of 150 - 1800 meters. It is a species of medium to large size: its hanging and thin pseudobulbs reach 40 cm in length. The leaves are deciduous, up to 6 cm in length.

Classification

Family: Orchidaceae Subfamily: Epidendroideae Tribe: Dendrobieae Sub-tribe: Dendrobiinae Genus: Dendrobium Species: Den. aphyllum Section: Dendrobium

Vegetative cycle

The vegetative cycle of Dendrobium aphyllum is divided into two phases: that of growth and that of rest. This is because winters in its natural habitat are quite dry, and the best way to survive during the dry period is to stop growing until the season changes. In cultivation, the rest period begins when the new pseudobulbs become almost mature. The wetting is reduced a little to allow the plant to remain completely dry for 4-5 days between one wetting and the next. Then this period is prolonged to arrive at 10-14 days of dryness between wetting. The specimens on raft are treated in the most "easy" way and get wet once every 5-7 days during the rest period. The temperatures in this period must not exceed + 19-20 ° C, the air humidity must be about 70%. The light must not decrease: 40000-42000 lux are essential, because otherwise the buds of the inflorescences will not develop. The rest period ends when future inflorescences begin to show. Temperatures gradually rise and wetting become more frequent and more abundant.

Placement

To facilitate its leaning way of growing, I recommend placing this species on a raft, putting some sphagnum under its roots. It is also possible to grow it in pots (with medium-sized pine bark as a substrate), but it will not be easy to direct the pseudobulbs that will need to hang down.

If Dendrobium aphyllum is placed in pots, it is highly recommended to take it outdoors when night temperatures exceed + 15 ° C. It must be placed in a very bright place, with a few hours of direct sun, and protected from strong winds and rains.

Light

Dendrobium aphyllum needs very strong lighting: 40000-50000 lux. It tolerates direct sun well, but in the hottest hours (from 12 to 15) the sun must be slightly shielded. The recommended photoperiod is 12-14 hours.

Temperature

Since this species grows at very different altitudes, it adapts to both intermediate-warm and intermediate or intermediate-cold conditions. However, I recommend not to overdo it with the cold. Summer temperatures must be + 24-26 ° C during the day and + 17-18 ° C at night, while winter temperatures (during the rest phase) must be at + 18-19 ° C during the day and + 10-12 ° C at night.

Air humidity

For bare-rooted specimens, the humidity must be about 70%. If Dendrobium aphyllum is grown in pots, it can also be lower: 55-60%.

Wetting

During the growing period, Dendrobium aphyllum is regularly and abundantly watered as soon as the substrate has become almost dry. Beware of specimens kept in the open air: most likely, despite being in pots, they will need daily wetting, especially in summer. During the rest period the plant gets wet as described in the section Vegetative cycle of this article.

Fertilizer

Dendrobium aphyllum only fertilizes during the growth phase. Use 1/2 of the dose indicated on the bottle of a special liquid fertilizer for orchids. Before fertilizing the orchid, it must be wet, to avoid harmful contact of the fertilizer with dry roots.

Flowering

The inflorescences develop along the entire pseudobulb at the end of the rest period. Each inflorescence bears from 1 to 3 flowers of about 4 cm in diameter. The well-developed specimens have truly spectacular blooms: they are covered with a flood of flowers. If Dendrobium aphyllum does not bloom, and is still healthy, the main causes are: 1) the lack of adequate light, 2) the absence of temperature changes between day and night (which must be at least 6 ° C), 3) too many wetting during the rest period.

Where to buy it

It is a fairly common species on the market. In Italy it is found under the name Dendrobium pierardii da Nardotto e Capello (go to the section Useful links).


Repotting

Periodically the dendrobiums tend to fill the container with new pseudobulbs in autumn we can repot our plant, using a good specific substrate for orchids.

If desired, it is also possible to propagate the plants by dividing the tufts of pseudobulbs or we can also simply remove the older pseudobulbs and keep only the young and swollen ones.

Dendrobiums sometimes tend to produce new plants attached directly to the nodes of the stems, called kieki, these young plants have their own roots, so they can be detached from the mother plant and repotted individually.


Curiosity

In Australia it is not at all difficult to come across beautiful species of Dendrobium. A plant with refined and fragrant flowers, much loved by the local population. È una delle piante più diffuse e più importanti tanto che la specie Dendrobium Phalaenopsis è stata scelta come emblema fiscale del Queensland ed è stata inserita nel francobollo da 25 centesimi e in quello da 1,20 dollari.

The Orchidee Dedrobium sono presenti nel libro di Wolverton, sulle 50 piante che aiutano a pulire l’aria degli ambienti chiusi come case e uffici.

I colori spettacolari del Dendrobium Phalaenopsis (foto Chip Sillesa CC BY-NC-ND 2.0)

Leggenda delle orchidee: si narra che ad un fanciullo di nome Orchide erano spuntati due seni femminili.

Un particolare che lo distingueva da tutti i ragazzi e anche dalle ragazze: era un uomo, ma per alcuni aspetti si avvicinava al genere femminile.

Era considerato un “diverso” e tutti lo evitavano. Una situazione che faceva stare molto male il giovane, il quale in preda alla disperazione si suicidò gettandosi da una rupe.

Proprio sul luogo della sua morte iniziarono a spuntare come per magia dei fiori bellissimi, tutti diversi tra loro ma con tante caratteristiche in comune.

Fiori eleganti e sensuali, dalla raffinata bellezza, chiamati Orchidee.


Origini, habitat e pratiche colturali: innaffiatura, concimazione, potatura, rinvaso, riproduzione.

Innaffiature e concimazioni.

The Orchidee Dendrobium, in prevalenza di origine asiatica e australiana, come la quasi totalità di Orchidee, pur prediligendo un ambiente umido, temono l’abbondanza d’acqua, per cui molto oculati debbono essere gli interventi di innaffiatura, lasciandosi guidare dal buon senso e dall’ esperienza, evitando di intervenire se il terriccio presenta ancora tracce del precedente intervento, riducendoli drasticamente durante la stagione autunnale, per eliminarli quasi completamente durante la stagione invernale, periodo durante il quale l’Orchidea prepara i nuovi boccioli per la interessante fioritura primaverile, caratterizzata da fiori il cui colore spazia dal bianco candido al bianco con svariate sfumature di colori.

Con gli interventi di innaffiatura si provvederà, con cadenza mensile, alle necessaria fertilizzazione della pianta, diluendo nell’acqua destinata alle innaffiature una limitata dose di concime per orchidee equilibrato, un concime in cui i varie elementi, quali Azoto, Fosforo e Potassio sono presenti in egual misura.

Se con le concimazioni si intende dare un impulso alla fioritura, la combinazione dei vari elementi vede una prevalenza di fosforo e potassio a discapito dell’azoto, fermo restando la soft dose complessiva, non perdendo mai di vista che le orchidee sono piante poche esigenti, circa la quantità di elementi nutritivi. Basti considerare allo spirito di sopravvivenza che le caratterizza in natura, dove riescono a sopravvivere anche con condizioni estreme, dal punto di vista nutrizionale. Ovviamente, durante la stagione invernale, sospendendo le innaffiature si sospendono anche gli interventi fertilizzanti.

Potatura e rinvaso.

Come la quasi totalità delle Orchidee, anche le Dendrobium non amano i frequenti rinvasi e gli interventi di potatura in senso lato.

Circa gli interventi di potatura dell'orchidea, nella fattispecie destinati a recidere gli steli fiorali per i quali la fioritura è giunta a capolinea, diciamo che l’intervento è indifferente, anche se il genere prevede la rifioritura sugli stessi steli, dal momento che in ogni caso la pianta darà vita a nuovi steli fiorali, steli nuovi in grado di assicurare fioriture più rigogliose. Tra, l’altro i vecchi steli, quelli che già sono stati oggetto di fioritura, possono dar vita ad una nuova piantina che può essere separata dalla pianta madre. L’eventuale taglio degli steli fiorali va eseguito con cesoie bene affilate, opportunamente sterilizzate.

Il rinvaso dell'orchidea, operazione da porre in essere quando il contenitore diventa insufficiente o malandato, dal punto di vista operativo, da un lato prevede la preparazione della pianta da rinvasare e dall’altro la preparazione della nuova dimora.

Con riguardo alla pianta da rimuovere dal vecchio contenitore, per cercare di limitare i danni e le ferite alle radici, il giorno precedente all’operazione la pianta va tenuta per un po’ di tempo in un contenitore con acqua leggermente tiepida, al fine di rendere le radici in qualche misura flessibili, la qualcosa ne limita lo stress.

Per quando riguarda la preparazione del nuovo “vaso”, si inizia proteggendo i fori di drenaggio con l’apposita griglia, segue uno strato di cubetti di polistirolo e/o altro materiale inerte, per realizzare un buon drenaggio. Dopo un ulteriore strato di substrato, preparato come di seguito, si depone e si fissa la massa radicale, lasciando tra le radici ampi spazi per una buona areazione e ossigenazione delle stesse.

Il substrato sarà costituito da una prevalenza di corteccia sminuzzata, cui va aggiunto dello sfango e pezzetti di materiale inerte come pezzetti di gommapiuma che trattengono un minimo di acqua per assicurare la necessaria umidità alla radici. Pertanto, il terriccio deve essere espressione di un perfetto equilibrio tra i vari elementi del composto, cui si aggiungono le caratteristiche drenanti e di areazione del Vaso, per materiale e fori di drenaggio dell'acqua.

Dendrobium coltivate in vaso: sottovaso e nebulizzazioni.

Alle Orchidee Dendrobium coltivate in Vaso in casa o rincasate durante la stagione invernale, bisogna assicurare i salutari interventi di nebulizzazioni, durante i periodi di intenso caldo e durante la stagione fredda con i riscaldamenti accessi che seccano l’aria.

Per assicurare alla Dendrobium un ambiente circostante adeguatamente umido, è opportunamente dotare la pianta di un sottovaso contenente argilla espansa bagnato. L’acqua contenuta nell’argilla, evaporando col calore dell’ambiente, umidifica l’aria circostante alla pianta. Gli interventi di nebulizzazioni, salutari per le piante in Vaso, diventano indispensabili per le Orchidee Dendrobium coltivate come piante epifite, in assenza di un vero substrato, alloggiate su zattere di sughero o tronchetti d’albero.

Tecniche di riproduzione.

Circa la riproduzione dell'orchidea dendobrium, a parte quella per seme tipica in natura, tra le varie tecniche vegetative, quella maggiormente diffusa è quella per divisione, che si realizza invasando i nuovi getti una volta che hanno messo le radici.

Il rinvaso è generalmente l’occasione per la moltiplicazione della pianta, grazie alla divisione dei cespi da invasare in nuovi contenitori.

Come per le specie Vanda e Cymbidium, anche per la specie di Orchidee Dendrobium, il mercato mette a disposizione una grande varietà di ibridi.

Ospite indesiderato: il ragno rosso.

The Orchidee Dendrobium sono piante resistenti che non si ammalano facilmente, ne sono facile preda di insetti, con eccezione del ragno rosso che potrebbe diventare un ospite indesiderato e la cui presenza richiede i necessari interventi antiparassitari, che in genere non vengono praticati preventivamente.


Video: Dendrobium Phalaenopsis Orchids! Intro to my Collection + Care Tips!


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