Dendrobium orchids are the second largest orchid genus in the world. Orchids are found everywhere in nature, from very hot climates to frigid zones. Their variety of form, habit and culture is staggering. Dendrobiums are from Southeast Asia and have a lower fused set of sepals that form a chin on the bottom of the bloom. Dendrobiums can be propagated by cutting, division and seed but seed is a method for professionals.
The dendrobium is a deciduous orchid that experiences the majority of its growth from spring until the end of summer and then has a corresponding rest period in the fall and winter. During dormancy, they lose their leaves and can tolerate full sunlight. In winter, the temperatures can dip to 40 degrees Fahrenheit and the plants need little water and no fertilizer. When spring arrives, you need to increase water and decrease light as the plant re-sprouts and prepares flower buds. There are Himalayan, Australian and New Guinea-type dendrobiums, each with slightly different characteristics and care.
Cuttings come from the offshoots, or "keikis," which are simply aerial shoots that arise from the parent plant. Keiki is a Hawaiian word that means "baby." A sharp clean knife is used to take 3- to 5-inch cuttings of the leaves, each with a couple of growth nodes or bumps along its surface. The cuttings are placed on a bed of moist sand and covered with plastic wrap to keep them moist. New roots will form from the cuttings in a few weeks and additional vegetative growth will sprout.
Division is probably the easiest method of propagation for any plant. At some point, the orchid will become root-bound in its pot and will require re-potting. This is a perfect time to divide it. You will need a very sharp and sterile knife to prevent the spread of disease. Remove the dendrobium from its pot and set it on a firm surface. Cut through the roots to create separate sections of the plant. Each piece should include four to five stems and a large chunk of the root system.
No matter what method of propagation you chose, the potting medium is one of the most important aspects of planting an orchid. While there are orchid potting mixes you can purchase, you can create your own. Orchids grow best in free-draining media which entails a soil-less composition. Bark chips alone make an excellent planting base or you can add charcoal or gravel. Potting soils conserve too much water and don’t offer the nutrition that these epiphytic plants require. In summer, water the orchids two to three times per week and half that in winter. Fertilize them with a slow release mix when they are re-potted. Cut off spent flowers and keep the dendrobium in a indirectly lit room