Strong light (over 2,000 foot-candle) is recommended. Inadequate light levels will result in spindly stems and thin leaves with little or no flowers. East or west windows in the summer and autumn and south windows in the winter and early spring all give plenty of light to grow dendrobiums well. Extended exposure to strong light or abrupt exposure of plants to high temperature in the presence of strong light can quickly cause permanent sunburn.
Most popular dendrobiums for the consumer market require warm temperatures to grow and flower. A temperature range of 90 to 65° F will satisfy the need of most hybrids. If temperature exceeds 90° F for extended periods, reduce light slightly so plants will not overheat. Lower temperatures during blooming will make the flowers last longer.
WATER AND FERTILIZER
Dendrobiums survive long periods of dry conditions that many face in nature. However, for best flowering, regular watering and fertilizing are needed. Roots of dendrobiums can not tolerate wet conditions for long that will result in root rot. Since growers use pots of various sizes and media with a wide range of water-holding capacities, it is not possible to give a watering frequency. As a general rule, water plants only when the medium in pots has become dry to the touch, but not bone dry. Stems with deep grooves indicate not having adequate water for too long. Dissolve half a teaspoon of a soluble fertilizer, such as Peters 20-20-20, MiracleGro, or similar, in one gallon of water. Use this fertilizer water at each watering when there is active growth and use it at every other or third watering when there is no active growth. Allow the excess water to drain freely at each watering.
Dendrobiums like to be root-bound. Do not repot them unless the new growth has come out of the edge of the pot. However, do repot them when medium has decomposed. Otherwise, root rot will be eminent. Potting medium can be a mixture of medium size bark, volcanic rock, hardwood charcoal, coconut husk chips, or sponge rock. Press the medium tight during repotting. With proper care, you will enjoy your dendrobiums for years to come.