The dendrobium family of orchids comprises merely four genera. Of these, three genera are not cultivated widely. The fourth, known as Dendrobium, includes numerous species, which according to a modest estimate, varies from 900 to 1,400 or even more.
Dendrobium species are natives of India, China and Japan all the way through Indonesia to Australia, New Zealand and the assorted islands of the Pacific. Orchids in Dendrobium species greatly vary in size as well as appearance.
The largest of these orchids grow up to a height of about 10 feet or even more. On the other hand, you would need a magnifying glass to see the flowers of the smallest ones. The color of the flowers of these orchids too vary greatly and they may appear in cream, white, yellow, red, orange, pink, purple, lavender and blue hues.
Aside from these colors the flowers of Dendrobium orchids may also have nearly all the imaginable combinations of these hues. Usually, the habitats of Dendrobium orchids include tropical highlands, monsoon-region forests in mountains, pine forests and steaming jungles.
Almost all Dendrobium orchids are epiphytes, but a few of them are lithophytic – growing and thriving in leaf molds on cliffs and rocks and pockets of moss. While some Dendrobium species grow fat pseudo bulbs, most of the other plants in this genus have slender, erect or pendent stems that are known as canes.
The canes grow from a rhizome, but they are unusually held tightly together. The inflorescence of these species carries anything between 1 and 100 or even more flowers. These inflorescences of Dendrobium orchids grow from the upper part of the canes.
The plants grow well even in small pots and hence they need not be repotted very frequently. These orchids essentially need lots of light and free movement of air. If you are growing them indoors, you need to place them on an east, west or south-facing window that is covered with thin curtains.
It is important to ensure that the humidity level is maintained high by misting the plants or placing the pots on top of trays containing wet gravels. Considering the wide range of plants in this genus and their greatly diverse structure, it is quite normal that all species belonging to the genus Dendrobium will be able to flourish under the same conditions.
The species discussed in this article can be categorized into one of the two classes. The first includes the cool-growing species, which are usually deciduous. You should provide these plants with enough water and fertilizer during their growth period and subsequently allow the orchids to rest for some time during the winter.
During the rest period, you either do not provide them with any water or only enough water to prevent the canes from drying up. When the plant are in rest they have a preference for cool night time temperature ranging from 40°F to 50°F (4°C to 10°C).
Usually, the warm-growing plants of genus Dendrobium are evergreen and they need to be provided with water all through the year. However, they will require less water during the winter months. Plants in genus Dendrobium are classified into several different sections.
It is not possible to discuss more than seven sections in this article owing to scarcity of space. However, all the sections included in this discussion are of horticultural importance. As it is expected, the cultural needs of this diverse group of orchids differ to some extent.
In case you have any doubts regarding how to treat the orchids in this genus, the best thing to do is to grow them in the same manner as you would grow cattleyas. However, compared to cattleyas, orchids in this genus require a little higher intensity of light.
If you notice that the leaves of some plants are drooping during the winter, you ought to know that it is an indication that these particular plants need to be kept somewhat dry during the winter months.
Callista is a small section of orchids belonging to genus Dendrobium that are native to Asia. The leaves of these species are deep green and have good substance, remaining confined to the upper portion of the distended canes.
You can grow these orchids in the same way as you would grow cattleyas. They can be grown in minimum temperatures of about 50°F (10°C), but would need less water during the winter.
While plants in this section have been used to develop some hybrids, usually orchids in this section are more prevalent in collections. A few plants of this section are discussed below. All these orchids are in bloom in spring.
Dendrobium densiflorum plants produce a four angled pseudo bulb and they grow up to a height of about 12 inches (30 cm). The flowering stem bears numerous yellow flowers having fringed lips.
The individual flowers measure about 2 inches (5 cm) across. The plants look stunning when in bloom, but the flowers do not last for a long period.
The plants of Dendrobium palpebrae are similar to those of Dendrobium densiflorum, except for the fact that this species bears white flowers with slightly orange hued lips.
Dendrobium trigonopus orchids bear waxy, yellow hued flowers whose lips are green at their base. The individual flowers of this species measure 2 inches (5 cm) across. The glossy flowers are striking and will attract your attention immediately.
Orchids in section dendrocoryne are found growing naturally along the coast on the damper area of the great dividing range in eastern Australia. These orchids may be epiphytes or lithophytes having leaves with good substance above the pseudo bulbs, which are somewhat slender as well as broader at the bottom.
Orchids of this section have been used to develop numerous hybrids in Australia. In fact, you will find several eye-catching hybrids that are of immense horticultural value both within the section dendrocoryne and integrating some other section of dendrobiums.
Four species of this section are discussed briefly below and they are generally grown and line breeding within each of them. These species as well as hybrids have produced flowers that not only have superior form but also wonderful colors. You should always grow these orchids in a bark-based growing media.
Dendrobium falcorostrum is certainly a cool-growing orchid that grows naturally in the Great Dividing Range at elevations of more than 3300 feet (1000 meters) in eastern Australia where the conditions are moist, cool and cloud forests.
This region of Australia frequently witnesses light snow dustings during the winter. This orchid species is an epiphyte. The fragrant flowers of this species are borne near the raceme terminal. The flowers have a pristine white hue and each measures about 1 ½ inches (4 cm) across.
The plants are in bloom in spring. The plants Dendrobium falcorostrum can grow in the same potting medium like the other orchids in this section. This orchid is known to flourish well when grown on a tree fern slab.
Since this orchid is a cool-grower, it does not prefer high daytime temperatures. Nevertheless, the plants require high intensity of light – even full sun – during the winter months. It is worth mentioning here that this orchid species is among the most attractive in the callista section.
Dendrobium kingianum is a familiar orchid that can be grown easily. This orchid is largely lithophytic in nature. The size of the plants is variable and they can grow up to a height of anything between 2 inches (5 cm) and 20 inches (50 cm). However, usually the average plant grows up to a height of 8 inches (20 cm).
Each inflorescence of this orchid species carries about six flowers that emerge from a bud close to the crown of the pseudo bulb. The individual flowers measure about 1 ½ inches (4 cm) in width and the color of the flowers can vary from white to pink to deep mauve.
In nature, these orchids have a preference for growing at an altitude of roughly 1000 feet (300 meters). Some plants have also been found to grow at an altitude of about 4000 feet (1200 meters). The plants of dendrobium kingianum have a preference for good light and you can grow them in the same potting medium which you use to grow cattleyas.
You need to ensure that the interval between waterings should not be much during the hot summer months so that the plants actually dry out. However, the potting medium should be kept drier during the winter months and fall as it would encourage better flowering in spring.
These orchids may have aerial growths or keikis (a Hawaiian term for babies) and produce roots. You can remove these aerial growths along with the roots and pot them separately. Alternatively, you may leave them on the plants to produce flowers at a later stage.
Dendrobium kingianum plants are capable of enduring temperatures as low as near freezing without being harmed in any manner. In fact, D. kingianum is among the a small number of orchids that usually succeed even in the hands of some people, who may actually not be knowing much about growing plants belonging to this family.
The plants Dendrobium speciosum are undoubtedly the largest in this section. This orchid produces anything between two and six leathery leaves and the racemes are long. Each raceme carries as many as 80 densely packed white to yellow flowers.
The individual flowers measure 2 inches (5 cm) or more in width. When these large orchids are in bloom they look stunning. This variable orchid species is native to Australia and is found growing naturally over a vast area ranging from northern Queensland downwards to Victoria.
Precisely speaking, the natural habitat of this species covers a distance of about 3000 miles (5000 kilometres) from north to south Australia. The southern forms of this orchid species are somewhat cool-growers and they need to be grown in the same way as you would grow D. kingianum.
Nevertheless, the Dendrobium speciosum plants have a preference for ample light and you can leave them in the full sun outside. These plants are capable of enduring light frosts, but need to be sheltered from rain and wind to preserve their flowers.
This dendrobium species is somewhat and is found growing naturally over a extensive latitude range. The pseudo bulbs of Dendrobium tetragonum are slender at their base and broader as well as four-angled at their top.
As a result of being top heavy, the plants have a pendulous growth. The length of the plants is also variable as in the case of Dendrobium kingianum. The flowering stems are short and each bear two to four yellowish or greenish, spidery flowers, each measuring about 5 inches (12 cm) in diameter.
These orchids are in bloom in spring. However, some northern forms of this species can bloom at any time of the year and these plants have a preference for higher minimum temperatures.
Dendrobium tetragonum is an epiphyte. If you are growing this orchid species you need to increase the intervals between watering in winter even it means results in the shrivelling of the pseudo bulbs to some extent.
Sometimes orchids classified in section eugenanthe are known as soft cane dendrobiums. However, using this term for these orchids is somewhat confusing. The orchids discussed below are all epiphytes and they are capable of enduring winter night temperatures as low as 37°F (3°C) provided the plants are kept dry.
This Dendrobium species is found growing naturally over a vast region – from the Himalayas downwards to the extent of Vietnam at altitudes reaching up to 4000 feet (1200 meters). The canes are as broad as a finger and grow up to a height of 20 inches (50 cm) and they have a tendency to shed their leaves as they mature.
The plants are in bloom in spring. The individual flowers are quite large, measuring about 3 inches (8 cm) in diameter. The color of the flowers varies from shades of pink to purple. A white form of this variety known as var. virginalis also exists.
The flowers appear in clusters of as many as three from the nodes on the upper nodes. In cultivation, this orchid species is capable of enduring temperatures near the freezing point. Even warm and hot summer weather does not create any problem for them.
You can grow these orchids in pots using the same growing media that you use for cattleyas. The longer canes of this plant have a tendency to be pendulous and hence stakes are used to keep them upright and offer their most excellent flower display.
If you want your dendrobium nobile orchid to bloom in spring, you need to follow some strict rules. Water the plants frequently in summer ensuring that they do not suffer due to lack of nutrients. Hence, you need to feed the plants properly. They require about 3000 foot-candles light during this period.
Subsequently, you should reduce the frequency of water supply to the plants from the beginning of fall and stop providing them with any nitrogen-based fertilizer. However, you need to continue feeding them with potassium and phosphorus.
The plants need additional light during this time and you may even grow them in full sunlight. Stop giving the plants any nutrient and water from the beginning of winter, but provide them with as much water so that the canes do not shrivel.
You may resume the normal watering and feeding once you find the buds appearing. In case you fail to observe these rules, the canes will grow exceptionally long and they would produce aerial growths or keikis (a Hawaiian term for baby) rather than bearing flowers.
You may remove these aerial growths or keikis and pot them separately after they develop roots.
Hybridizing several dendrobium nobile species for over 100 years, sometimes even including other species of this family, has led to the development of tetraploid plants having chunky, shorter canes along with larger, better shaped flowers that last for a long time.
These hybrids are modern plants and their flowers are considerably beautiful. In present times, these hybrids are also referred to as Yamamoto hybrids, named after the famous Japanese hybridizer Mr. Jiro Yamamoto.
Compared to any other hybridizer before him, Mr. Yamamoto has contributed a lot to being perfection to the Nobile hybrids, which are often referred to as Yamamoto Dendrobiums. It is important to note that you should grow these hybrids in the same way as you would grow the plants of Dendrobium nobile species.
Dendrobium aphyllum is native to Southeast Asia and is now grown extensively. This orchid species is showy producing long, pendulous canes. As the canes mature, they drop their leaves in winter. The white to yellow flowers are borne along the length of the canes.
The individual flowers measure about 2 inches (5 cm) and the plants are in bloom in spring. You may grow this orchid species in the same manner as you would grow nobile dendrobium hybrids.
However, the plants of Dendrobium aphyllum have a preference for somewhat higher minimum temperature (50°F/10°C) during the winter months. It is worth mentioning here that Dendrobium pierardii is very similar to this species – possibly both are the same species.
Dendrobium fimbriatum is native to Southeast Asia and this orchid is a cool-growing to warm-growing species. The plants produce leafless, long canes that bear numerous flowers in spring. The individual flowers of this orchid species measure about 2 inches (5 cm) across.
The flowers have a golden yellow hue with a nice-looking fringed lip. You should grow plants of this species in the same way as you would treat nobile dendrobiums. However, these plants require some watering during the winter months too.
Dendrobium heterocarpum (aureum)
This Dendrobium species is not only widespread, but also variable. Nearly all varieties of Dendrobium heterocarpum (aureum) in cultivation are cool-growing and they should be grown in the same ways as you grow Dendrobium nobile during the winter months.
In winter, these plants shed their leaves prior to flowering on the leafless canes at the onset of spring. The individual pale yellow flowers of this orchid species measure about 2 inches (5 cm) in diameter. This species was used for developing the early nobile-type hybrids.
Nigrohirsutae is an Asian section that produces stout canes and deep green colored leaves. The canes of this orchid are covered with brown or black bristles. You can grow the plants of this species with the same intensity of light as well as potting media that are required for growing cattleyas.
In addition, the atmosphere needs to be humid, while the temperature requirements of the plants differ depending on the species. Plants in this section of Dendrobium orchids are in bloom twice a year – once in winter and again in spring.
The sepals and petals of the flowers are white, but they appear to be rather paper-like. The flowers last for a long time too. Although several hybrids have been developed within this section, below are some of the species that are attractive as well as somewhat common in collections.
These orchids are evergreen dendrobiums, as these plants shed their leaves in winter. At the same time, you need not keep these plants dry during the winter months.
Dendrobium bellatulum is a dwarfish orchid species whose canes grow up to a height of about 4 inches (10 cm). The individual flowers of this orchid measure about 1 ½ inches (4 cm) across and have red-orange hued lips.
The plants are somewhat cool-growing and require a minimum temperature of 50°F (10°C) during the winter months. D. margaritaceum is a similar species but much more small compared to Dendrobium bellatulum.
Dendrobium formosum is a kin of the species D. infundibilum. Despite the fact that this orchid grows naturally at high altitudes, it appears that the plants in cultivation require warmer minimum night time temperature (about 54°F or 12°C) to flourish as well as produce their best flowers.
The canes of Dendrobium formosum grow up to a length of 18 inches (45 cm) and they carry star-shaped white flowers. The flowers of this species are larger compared to those of Dendrobium bellatulum and Dendrobium infundibilum.
Dendrobium infundibilum was originally found growing at somewhat high altitudes and it is a cool-grower. The canes of this orchid species grows up to a height of about 16 inches (40 cm) and they bear flowers near the top of mature growths.
The individual flowers measure about 3 inches (8 cm) across. These plants are somewhat common in cultivation. Another similar species is D. jamesianum, but it is possibly the same species.
Orchids in this dendrobium section are native to Irian Jaya and Papua New Guinea or far off islands, some of them located as far as in the Pacific Ocean. The plants in this section are small and some of the species have been in cultivation rather recently.
These plants are native to high altitudes and they seldom survive when grown in places at sea level within the Tropics, where they are found. However, it is not difficult to cultivate these orchids in places having temperate climatic conditions, where they are cool-growers.
These plants are capable of enduring temperatures as low as near freezing, but loathe being grown in intense heat and aridness of summer. They require repeated misting and excellent air circulation during summer, as these help them to thrive the prevalent conditions.
However, they mostly require being sheltered in shade to ensure that the leaf temperatures remain low. A number of orchid species in Oxyglossum section sometimes grow in full sun in the wild, but you should never grow these orchids in the same condition when in cultivation.
In all, the Oxyglossum section comprises 28 orchid species. All of them have a tendency to produce flowers that appear “upside down”, with the lip appearing uppermost. All the species discussed below can be grown in the same conditions.
As far as the potting media is concerned, just about everything has been tried, including sphagnum moss. When growing in nature, these orchid species become wet and dry alternately everyday and, hence, it is important to grow these plants in a medium that dries out quickly.
Perhaps, the safest potting medium for these plants is any bark-based mix that is used for growing cattleyas. However, you need to ensure that none of the potting medium should be allowed to remain dry at their roots for a maximum period of a day.
As of date, no firm rules have been laid down for growing Oxyglossum orchids. Hence, you are free to experiment with the plants to find out what potting medium, amount of watering, temperature and light suit the plants most.
The original name of this orchid species was Dendrobium sophronites. German botanist Rudolf Schlecter named the species such as it reminded him of an unrelated species from Brazil called Sophronitis coccinea.
In fact, this species is considered to be the jewel in the crown of the genus as it bears attractive flowers that remain intact and in perfection for about six months or maybe even longer. The plants of this species are relatively small, growing up to a height of only 2 inches (5 cm).
They produce several leaves having substance on top of undersized pseudo bulbs. The flowers of Dendrobium cuthbertsonii appears to be larger than the plant itself and the individual flowers measure about 1 inch (3 cm) in diameter. A plant grown in a 2 inches (5 cm) pot can produce as many as a dozen flowers.
Usually, the color of the flowers is orange or scarlet, but some even produce yellow, pink or magenta hued flowers. In addition, you may come across plants bearing bicolour flowers having a blend of the above mentioned colors.
This orchid species has a unique feature and that is the presence of thick prominent warts on the top surface of the leaves. These are not present in any other orchid. However, the purpose of these warts is yet to be understood.
Dendrobium cuthbertsonii is found growing naturally in Papua New Guinea and Irian Jaya at elevations of up to 10,000 feet (3000 meters). This species is an epiphyte and grows on trees covered with moss where there is heavy shade.
It also grows in the form of a terrestrial in the open on elevated grasslands. This is an indication of the fact that Dendrobium cuthbertsonii plants are capable of being accustomed to an assortment of conditions even in cultivation.
In fact, fine plants of this species have been cultivated on tree-fern slabs. It has been found that plants propagated from seeds have a tendency to grow more easily compared to the plants that have been transplanted from their native habitat.
These plants are a favourite of the two-spotted mites, which can assault and practically destroy these orchids. Since it is not possible to spray insecticides below the leaves, it is advisable that you hold the pot upside down and rinse the foliage in a miticide to get rid of the pests.
Dendrobium laevifolium in section Dendrobium cuthbertsonii is a compact plant growing up to a height of about 4 inches (10 cm). The plants usually produce only two leaves above the flask-shaped pseudo bulbs. The flowers emerge from the leafless mature bulbs.
These orchids do not have any specific blooming season and may appear at any time of the year, especially in fall when the plants are in cultivation. In fact, nearly all the orchids in this section that are in cultivation have their origin in Rossel Island, located east of Papua New Guinea.
The color of the flowers is either deep rose or mauve and their size is similar or a little larger than those of D. cuthbertsonii.
In addition to the above, plants bearing lighter hued colors, which also include white, have been found in the Solomon Islands, Bougainville, Vanuatu and other places. This species bears very attractive flowers and is slightly less demanding in cultivation compared to D. cuthbertsonii.
Dendrobium prasinum is worthy of being cultivated more extensively. This orchid species is similar to D. laevifolium, but the deep green leaves of the former possess more substance. In addition, the flowers of this species are white. This orchid is found growing naturally in the Fiji islands.
Dendrobium sulphureum is a variable orchid species. The plants of this species grow up to a height of about 4 inches (10 cm). The plants produce several leaves on the upper segment of the slender, cylindrical, bunched pseudo bulbs.
The flowering stem carries one or two flowers, each of which measures about 1 inch (2.5 cm) in length. The color of the flowers is either yellow or yellowish-green with a striking and contrasting orange hued lip. Dendrobium sulphureum is an attractive orchid species and you can grow it in the same manner as you would grow the other oxyglossum plants.
Among all the Irian Jaya species in section oxyglossum, Dendrobium vexillarius is found in most abundance. This species is epiphyte in nature in its natural habitat, which extends over a vast range. The natural habitat of this species is at an altitude of up to 10,000 feet (3000 meters) or higher.
The color of the flowers varies from blue to dark crimson. It is a rather taller plant compared to other orchid species in this section. The pseudo bulbs of D. vexillarius are thin, distended at their base and have two to three leaves at their apex.
The individual flowers of this orchid species measure up to 1 ½ inches (4 cm) across and they appear in clusters of quite a few flowers. At the top of the pseudo bulb, often more than one flower stem emerges from the same node.
According to some growers, it is easy to grow Dendrobium vexillarius plants, while there are others who say that it is rather difficult to cultivate them. However, it is still not clear why the growers differ on this issue.
Nevertheless, this orchid species is a valuable plant to possess. If you are growing D. vexillarius, you need to provide the plants with the same conditions and give them the same treatment that is given to other orchids in section oxyglossum.
Section phalaenanthe comprises just a few orchid species, but two of them are very noteworthy – Dendrobium phalaenopsis and Dendrobium biggibum. Often both these orchids are considered to be the same species.
They are native to Indonesia, north or eastern Australia and Papua New Guinea. In general, the canes of these orchids grow up to a height of 12 inches (30 cm), but some can grow much higher. The canes are cylindrical and somewhat distended in the middle and produce very few leaves at their apex.
The flower stem of these orchid species carry several white flowers having shades of pink that intensifies into deep purple. The individual flowers measure about 2 inches (5 cm) or even larger. The flowers last for a long time. Dendrobium biggibum, also known as Cooktown orchid, is the state flower of Queensland in Australia.
The shape of the flowers reminds one of those of an unrelated genus – Phalaenopsis, which is also known as the moth orchid. These orchids grow naturally in places having hot and wet summers and slightly arid winters.
The conditions prevalent at their native habitat are an indication of the requirements of the plants in cultivation. Irrespective of the season, the plants need to be dried fast between watering. Hence, ideally you should use a potting medium that drains water quickly.
However, these plants are capable of enduring very high intensity of light. If you grow these orchids indoors, they would actually require a minimum temperature close to 60°F (15°C) all through the year. Precisely speaking, the orchids in this section are tropical plants.
Perhaps the Dendrobium phalaenopsis plants in cultivation are a product of line breeding with plants bearing flowers of impressive size, color and confirmation over many generations. This orchid has also been widely used for hybridization with plants of other sections, especially those belonging to section Spatulata.
It is quite easy to grow these orchids and they are shipped from different countries in Southeast Asia. They form a part of the multimillion dollar cut-flower industry across the globe.
If you reside in a place having warm temperate climate, you should try to grow Dendrobium biggibum “compactum”, which is a smaller-sized plant, producing flowers freely. This orchid is native to Queensland. Many of these orchids flourish well when grown in places having subtropical climatic conditions, like in Florida.
Plants in the section spatulata were earlier known as ceratobiums. A prominent characteristic of the flowers of this species is that the twisted sepals that habitually grow vertically. The plants in this section have been popularly named as the “antelope orchids” owing to this special trait of the sepals.
Usually the flowers of these orchids last for a long time. Nearly all the species in this section are natives of sea level or low elevation regions and are certainly warm growers. These plants require a minimum night time temperature of 60°F (15°C).
Providing these orchids with ample light as well as a warm and humid conditions prove to be beneficial. You may use the same potting medium for these orchids that you use for cattleyas. However, ensure that you grow these plants in small pots all through the year and provide them with repeated wet and dry cycles.
The tall canes are yet another characteristic of these orchids. The leaves of the plants remain confined to the upper portion only. The flower stems bear numerous blossoms that emerge from the nodes of the leaves on the upper part of the stem. Brief descriptions of a few species of this section are given below.
This orchid species in native to Australia and Papua New Guinea and they are found growing on melalecuca trees. Each flower stem of Dendrobium canaliculatum plant bears 50 or even more fragrant flowers.
The individual flowers measure about 1 inch (2.5 cm) across and the plants are in bloom twice a year – in winter and then again in spring. The petals of the flowers are white and yellow, while the sepals have a purple lip.
Compared to other orchids in this section, Dendrobium canaliculatum plants should be kept drier during the winter months. Compared to other spatulatas, this orchid is a smaller plant and has been used extensively for hybridization.
This is a very familiar orchid species which grows naturally over an extensive geographical area. The individual flowers of Dendrobium gouldii measure about 2 ¼ inches (6 cm) in diameter. The flowers have either white or pale violet hues with very uncommon golden yellow forms. This species is also used extensively for hybridization.
Dendrobium stratiotes is a truly majestic orchid species whose canes grow up to a height of 39 inches (1 meter) and bears large flowers that last for a long time. While the petals of the flowers are white, the sepals have a yellow hue with a violet lip. The plants of this orchid are in bloom all through the year.
Dendrobium tangerinum is a colourful orchid that was earlier grown under the name “Tangerine” for many years. The individual flowers of this orchid measure about 3 inches (7.5 cm) across and its petals have a vivid orange hue.
The sepals as well as the lip are yellow hued. This orchid has also been used extensively for hybridization and it has been a parent of several beautiful hybrids.