Orchids are the largest family of plants on the planet. Native to Asia, Dendrobiums are one of the largest genera of orchids. Their natural habitat encompasses many climactic zones, so the cultural requirements of Dendrobiums vary considerably. Dendrobiums make good houseplants but they do require careful attention for success. These growing tips are for Dendrobium hybrids, the type of Dendrobium orchids most commonly available.
Some Dendrobiums are evergreen and some are deciduous.
Dendrobiums need bright light to flower well. Indoors, place them in an east or west window, or a south window that’s lightly shaded. Outdoors, they can handle up to half a day of sunshine, but if the leaf edges darken or the leaves turn pale or yellowish-green, move them into a more shaded location. Dendrobiums that receive proper light levels have olive-green leaves and remain erect without much staking.
Dendrobium flower forms vary.
Dendrobiums are epiphytes, growing in the wild in the leaf litter that collects in tree crotches. Mimic that environment by using a specialized orchid potting medium that contains pieces of bark and allows water to drain quickly. Use a small pot with many large drainage holes and repot every two to three years with fresh growing medium.
Keep your Dendrobiums evenly moist while in active growth and flowering. You may need to water them twice a day or more if they’re summering outside. Use distilled water, or if using tap water, allow the water to sit overnight so chemicals such as chlorine can evaporate. Dendrobiums need a rest period after flowering, during which the planting medium should be allowed to dry between waterings. Deciduous varieties need no water in the winter when the stems are leafless.
Dendrobiums grow best with daytime temperatures of 80 to 90 degrees Fahrenheit and nighttime temperatures 15 to 20 degrees cooler. They tolerate even warmer temperatures if you keep the humidity around the plants high and air circulation is good. Temperatures below 50 degrees cause leaves to drop.
Growing ferns near Dendrobium orchids helps keep the humidity high.
Dendrobiums need 50 to 60 percent humidity, a level difficult to achieve in home environments, particularly in the winter. Grow these orchids on pebble trays and if necessary, use a humidifier in the winter. Mist the leaves and roots often.
Dendrobium flowers often have distinct markings.
Feed your Dendrobiums regularly while they’re in active growth and not at all while they’re resting. Use either a balanced 10-10-10 NPK fertilizer or one specially formulated for orchids. Apply a quarter-strength solution to the plant weekly.