From the Greek dendro(a tree) and bios(life) established by Olaf Swartz 1799
This genus consists of approximately 1100 named species, making DENDROBIUM the second largest genus in the Orchid family. Members of the genus vary tremendously in plant, flower form, size, flower color and fragrance. Plants are distributed in the wild from sea level lands or river banks to high elevation rain forests or snowy mountain ranges. The cultural requirements are variable, so we recommend careful research to obtain as much specific information as possible regarding the peculiar needs of each type. Please consider the suggestion list under "Recommended Reading'' below.
Dendrobiums can generally be handled as cattleya during the growing season with night temperatures In the 6O° F-65° . (15°-18° Celsius) range; growing season In the northern hemisphere occurs from April-October. Good light, air circulation, and drainage are essential for successful culture here. Regardless, should your plants not flower in the first season, try moving them to a different location in the growing area to give more or less light, warmer or cooler temperatures or more air circulation.
Where a resting or dormant period is recommended, reduce the frequency of watering enough to prevent severe dehydration or shriveling of the pseudobulbi. Occasional misting may be adequate to maintain the plant while inducing the dormancy which preceeds flowering. Do not fertilize during the dormant or resting period.
THE NOBILE GROUP
Examples - nobile, chrysanthum, devonianum, topaziacum, and their hybrids
Plants in this group loses their leaves in the fall. They require minimum night temperatures of 50° -55° F. (10° -13° Celsius) from late fall through their winter flowering. At the end of summer, all applications of fertilizers containing nitrogen should cease. Do not use slow release fertilizers for mature or flowering-size plants. When the shorter days and cooler night temperatures of early fall arrive, start to reduce watering volume and frequency (only enough to preclude severe shriveling of the pseudobulbs). The combination of cool, longer nights, and lower water amounts and the absence of fertilizer will create the dormancy which ultimately induces flowering. As the flower buds mature, the new growth usually will begin to appear. Once new growth is noticed, the normal watering and fertilizing routines may be gradually resumed. Use care in watering, so the new growth is dry before the cool of the evening.
THE ANOSMUM GROUP
Examples - anosmum, friedericksianum, heterocarpum, lituiflorum, parishii, pierardii, primulinum, aggregatum , jenkinsii and their hybrids
Most plants in this group are deciduous, the exceptions being lind and jenkinsii. Recommended culture for these is similar to that of the Nobile Group. However, fall-winter night temperatures may be slightly higher,i.e.55° -60° F (13° -15° Celsius). This group will mature the new growth prior to dormancy. So begin the dormancy treatment, reduced water, fertilizers, etc, when the new growth is completed in the early fall. Some plants in this group may not flower until late spring. The new growth usually begins when flowering is complete.
THE FARMERI GROUP
The plants in this group do not lose their leaves. They are evergreen species which do not go dormant during the year. However, for best results these plants should be allowed to experience cooler temperatures during the fall, preferably with 50° -55° F. (10° -13° Celsius) nights. If the cooler night temperatures can not be provided, then growing the plants slightly drier during the fall-winter will often work. Do not without permit the plants to completely dry out as in dormancy.
THE FORMOSUM GROUP (formerly the Nigrohirsute)
Examples - dearei. formosum, infundibulum, jamesianum, pulchellum and their hybrids
This group is easily distinguished from the other groups, by the easily seen black hairs on the stems of the plants. Particularly noticeable on the young plants or new "canes". These evergreen species enjoy similiar conditions as cattleyas; however the best flowering response results from exposure to winter night temperatures of 55° - 60°F. (13 -15 °Celsius). The flowers are fragile looking and often thin substance, but are very long lasting. As with most new growth, be very careful not to overwater just as the new growth matures.
THE 'CANE TYPE' GROUP
Examples - antennatum, canaliculatum, ciliatum, discolor, dixanthum, gouldii, leonis, and their hybrids
These evergreen dendrobiums should be grown as cattleyas year 'round, but avoid temperatures below 60°F. (15° Celsius). Although species of this group are not always available, their more common hybrids are. Their hybrids have become the most popular dendrobiums among orchid enthausists. In fact the plants in this group are generally in year around growth and produce multiflowerings. These traits in part explain their popularity. The flowers of many of the 'cane-type' hybrids are relatively large, long-lasting, and are available in a multitude of colors.
THE PHALAENOPSIS GROUP
Examples - bigibbum, phalaenopsis, superbiens, dicuphum
Also evergreen, these species and their hybrids should be kept warm all year. Do not expose these plants to temperatures below 60° F. (15° Celsius). This group is best grown under cattleya conditions. The mini dendrobs are derived from compact, small flowering varieties of this group. The minis should be treated exactly as their bigger cousins in this group. As with other dendrobiums, care must be exercised in not overwatering between flowering and appearance of new growth. It Is not unusual for these plants to lose some leaves during the year.
POTTING MEDIUM. FERTILIZER. CONTAINERS
Use a well-drained potting medium such as tree fern, fir bark, charcoal or stone to grow dendrobiums. You may also use osmunda, tree fern, or cork plaques/slabs. In any case, repot only as frequently as may be necessary to keep the potting medium fresh, avoiding severe decomposition which impairs drainage and air circulation in the root zone.
The fertilizer formula should match the potting medium. Use 20-10-20 with tree fern, charcoal, or various inorganic aggregates, but use 30-10-10 with fir bark. We recommend non-urea based fertilizers at half strength. Non urea fertilizers provide 100% immediately available nitrogen, which urea based fertilizers do not. We recommend Grow Mor fertilizers , which also have micro nutrients, to provide strength for the new growth, as well as support for the flowers.
When repotting is necessary, accomplish the task when your plants are in growth. At that time, dead or nonfunctional bulbs may be removed. Be certain, of course, to retain enough physical structure to keep the plant strong. Remember that leafless bulbs still serve as storage facilities for food and water. Always underpot. The underpotting encourages flowering. Slow release fertilizers may be sparingly applied to the surface of the potting medium during the growing season to promote vigorous growth when plants are given higher light intensity.
- Home Orchid Growing, by Rebecca Northen
- Orchids & How to Grow Them, by Gloria Jean Sessler
- Orchid Care, by Walter Richter
- Encyclopedia of Cultivated Orchids. by Alex D. Hawkes
- Growing Orchids Book Three. by J. N. Rentoul
- Dendrobium Orchids of Australia by Walter T. Upton
- All About Orchids by Charles Marden Fitch
- The Illustrated Encyclopedia of Orchids, by Alec Pridgeon