Culture of Dendrobium moniliforme – the Japanese Stone Orchid
Dendrobium moniliforme prefers moderate to bright light levels, from 2000 – 3500 foot-candles. If you are growing under fluorescent lights, keep the plants about 6″ from the tubes. Under high-intensity lamps, grow approximately 4 feet (1 meter) from the fixture. This plant can be grown on windowsills given an east, south, or west exposure. Plants may be grown outdoors in the summer with filtered sunlight.
This plant is a cold to hot grower. High temperatures can be as great as 100º F during the day, with a 10º to 15º difference at night. During fall and winter months, day temperatures can be below 30º F, but plants should stay on the drier side during cold periods. It is critical that plants be exposed to temps in the 50’s or lower (freezing temperatures are absolutely fine for this species) for at least a couple weeks in order to bloom well in the spring. Without a cold period, plants will grow well but produce fewer flowers.
Should be kept above 40%. Use humidity trays or a small room humidifier when growing on windowsills.
Water & Fertilizer
Use clean water such as rainwater, distilled, or reverse osmosis water if possible. Flush the plant regularly, especially if using municipal or well water. Never use artificially softened water. Use ample water and fertilizer in spring and summer while the plants are in active growth and in flower, reducing quantities during cooler winter days. To maximize flowering, give plants a dry season in winter. Lightly mist plants frequently, but water once every two weeks or so. Plants that are watered well through winter tend to produce keikis rather than flowers in spring. If using rain, distilled, or reverse osmosis water, add some municipal or well water to supply the necessary calcium and magnesium.
Dendrobium moniliforme blooms primarily in late winter or early spring and sometimes again in late summer. The inflorescence has one or two flowers and may have several inflorescences per cane. The fragrant and long-lasting flowers may be white, cream, yellow, green, or pink.
Repotting of this plant is preferably done in the spring and early summer, every year if in moss. Clay, plastic, or net pots, or wood baskets will work. In my experience, closed pots are better to keep moisture high around the roots in summer; however, many people grow this plant in baskets or on mounts (this requires greater attention to watering). Pay attention to how your plant is potted when you receive it: plants often prefer the medium to which they have become accustomed.
Traditionally, Japanese grow Dendrobium moniliforme (Choseiran) mounded in moss as we see fukiran potted. Note that mounds are hollow, not tightly packed balls of sphagnum. I have had great success growing in this manner; however, I have seen some really beautiful specimen-sized plants grown in bark or directly mounted on stone.