Culture of Dendrobium moniliforme – the Japanese Stone Orchid (Choseiran)
Dendrobium moniliforme (also referred to as Choseiran or Sekkoku in Japan) prefers moderate to bright light levels, from 2000 – 3500 foot-candles, although they will still grow in lower light. 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.
Dendrobium moniliforme 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 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. In Japan, varieties with beautiful leaves are sometimes kept warm to prevent leaf drop although this inhibits flowering.
Water & Fertilizer
Use clean water such as rainwater, spring water, or reverse osmosis water if possible. 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 drier season in winter by allowing them to dry completely between waterings. Plants that are watered well through winter tend to produce keikis rather than flowers in spring. As with all orchids, if using rain, spring, or reverse osmosis water, make sure to use calcium and magnesium supplements.
Dendrobium moniliforme blooms primarily in late winter or early spring and sometimes again in late summer. Each inflorescence has one or two flowers and may have several inflorescences per cane. The fragrant flowers are usually be white or cream colored, but can also be found in pink or yellow.
Repotting is preferably done in the spring or early summer, every year if in moss. Clay, plastic, or net pots will work. Closed pots will require less frequent watering, however I have found the plants grow better and produce fewer keikis when they dry out faster as when mounted or grown in mesh pots. I have had great success growing this species mounted.
Traditionally, Japanese grow Dendrobium moniliforme are 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.