LIGHT: Dendrobiums require a good deal of light and can take full sun in WINTER. Under one layer of house screening, they can remain on a patio all year if protected from the hot western sun in summer. Good air circulation is important.
TEMPERATURE: In general, Florida temperatures seem to be ideal for the growth of dendrobiums. They can survive in temperatures down to 32° , but will not grow at this temperature. During active growth (spring, summer and early fall) they grow best at 55-60° or above – and will tolerate up to 85° or even higher. 50-60% humidity is ideal. If the plants are indoors in winter, place over a tray with pebbles and water, or mist to keep humidity high enough. Do not allow plants to stand in water.
WATER: During active growth periods, water generously and feed often (see below). Lows of 50-55° are ideal. Dendrobiums prefer small pots and like to be somewhat rootbound – therefore do not overpot. They also grow well on plaques. Water twice each week during active growth and let water run through completely. When growth has been completed in the fall, provide cooler temperatures (50° or a little below) and water only enough to keep stems from shriveling. Leaves will be lost – this is normal. Flowers will appear first as buds from leafless stalks. When this happens, normal watering should be resumed. When flowering is finished, resume the cool dry regime until new growths are well started. Failure to reduce temperature and water during this time will result in good growth but few flowers. Do not be concerned when leaves are lost – new ones will appear in spring if plant is health.
FEEDING: Apply a balanced fertilizer once every two weeks if the medium is gravel or osmunda, or if the plant is on a plaque. Peters 20-20-20 is suitable. If the medium is fir bark, use a high nitrogen fertilizer (Peters 30-10-10). Use any of these foods once every two weeks at full strength or, as an alternative, try feeding once each week at ½ strength. Be especially careful to feed adequately during active growth.