JARS v45n2 - Pleiones: Orchid Companions for Rhododendrons

Pleiones: Orchid Companions for Rhododendrons
Richard Cavender
Sherwood, Oregon

I first became acquainted with pleiones while visiting a friend's commercial greenhouse. He was going out of business because of ill health and was trying to find homes for a few items. He pointed out several flats of rather ugly brown leaves and said I ought to take those home. This was late November and I was not really impressed, but I loaded the flats on the truck with a couple of tree ferns and several citrus trees. All went into a cool poly house and were forgotten for the winter. Spring was a real surprise. Those brown leaves were sprouting BEAUTIFUL flowers. Closer inspection revealed shoots emerging from small bulbs and opening into lovely orchid flowers. There were several varieties, and as the season progressed two rose-lavender varieties appeared and, finally, a pure white one.

My wife and I enjoyed the spring display of flowers but, with the onset of rhododendron season, soon lost interest in the green leaves that followed. This went on for several years. We did repot them one winter, the old pots having become swollen completely out of shape with good sized bulbs. We now had about twenty flats of these little oddities and, while a grand sight in bloom, they were starting to take up a lot of scarce greenhouse space. Fate would have it that I should mention the pleiones to Lucy Sorensen, owner of Bovees Nursery. She was most enthusiastic and we soon struck a bargain to sell a few. To say that they sold like hot cakes would be an exaggeration, but they were fairly popular and the price got my attention. At this point, names suddenly became important. To my chagrin, I discovered two cultivars with the disturbing habit of invading their neighbor's flat.

Pleiones grow from a dark green or maroon-purple pseudobulb. One, two or sometimes three sprouts appear in the spring, the flower generally opening before the leaves appear. As the flowers fade, a single leaf or, in a couple of species, two leaves appear. Over the summer a new pseudobulb forms at the base of the sprout and the original starts to wither away. The leaves die in the fall as the plants prepare for winter. In several clones, small whisker bulbuls may form atop the larger one. These remain attached to the dried leaf and are easily spread around. Pleione formosana and the cultivars 'Oriental Splendor' and 'Blush of Dawn' are particularly adept at this method of travel. They had almost crowded out two less prolific clones. To add to my problems, the plastic tags had become brittle and faded. I managed to reassemble the tags enough to decipher some names, but the problem was which plants belonged to those names. Several years of observation, sorting, educated guessing and finally the appearance of a new book on the subject cleared up the mysteries.

Not knowing any better I planted a few outside under a pine tree on the north east corner of our house. They have bloomed in this location now for over six years and are spreading nicely. They and Cyclamen hederifolium enjoy the deep layer of needles. Pleione bulbocodioides is pictured in just these conditions in a Journal article on a 1986 visit to Yunnan, China (Vol. 43, No. 3). In 1988 I planted another patch in a more exposed location in the back yard. It is still in full shade but doesn't have the deep layer of pine needles for protection. It came through the cold of February, 1989 with no problems. Visitors to Cecil and Molly Smith's garden may have noticed the small patch next to the rock wall by the front path. Cecil says they have been there for over fifteen years. Two years ago the garden committee tried planting more pleiones in other spots in the garden. Only one patch survives. The reasons for the disappearance of the others is not clear but they may be attractive to rodents. I know that slugs LOVE the flowers and may hollow out the pseudobulbs.

There have been several mentions of pleiones in Journal articles on China. The most recent was by Gwen Bell in the Spring 1990 issue. In most cases pleiones were found growing in moss, pine needles or in rock crevices. These locations would indicate that pleiones require good drainage. In pots or pans I use a mix of equal parts of peat, bark and pumice or perlite. Shallow pans are preferable and pleiones don't mind crowding. Don't water until the sprouts begin to show and then sparingly. Roots form at about the same time as the flowers. Keep evenly moist as the leaves emerge and feed regularly. Avoid granular fertilizer as it may lodge in the cups of the base of the leaves and burn. When the leaves start to brown in the fall, stop watering and store in a cold greenhouse or frame where the nights drop near or just below freezing. This chilling is necessary for flower development.

In the garden, select a site with excellent drainage. They will not tolerate being frozen and thawed regularly, so choose a spot out of morning sun when there is frost - a slope, a raised bed containing plenty of humus such as bark or coarse peat and coarse grit or the cracks in a rock wall. Pleiones need shade, at least afternoon shade, preferably full shade and protection from winter wet. A sheet of glass works, but planting under large camellias, rhododendrons or conifers is much more attractive. They will grow on the surface of the soil under the mulch much like cyclamen, sending roots into the soil for nutrients but keeping their pseudobulbs up out of the soggy soil.

Pleiones are colorful, ranging from pure white to butter yellow, bright rose-purple to pale lavender. Their flowers are larger than bletillas, about the size of cymbidiums. Most are spring blooming with a couple blooming in the fall. They are native to Taiwan, China, Nepal and throughout the Himalayas. The ones offered most often are P. formosana , P. bulbocodioides , P. limprichtii , or their hybrids. There has been considerable confusion over the yellow species, P. forrestii . A pale yellow form introduced by George Forrest has been in cultivation for many years under the name of P. forrestii . Recent studies have shown that it is in fact a hybrid. Now known as Pleione X confusa , it is a nice light yellow but no comparison to the real P. forrestii that has been recently introduced to cultivation. Pleione bulbocodioides has also undergone a name change. Grown for many years under the name P. yunnanensis . P. bulbocodioides is a bright rose-purple, while P. yunnanensis is a pale lavender. We are indebted to Phillip Cribb and Ian Butterfield for their work in unraveling the complexities of the genus.

Many fine hybrids are also becoming available and some are spectacular. So are their prices! Quotes from 50 to 90£ are common from English sources, and I was recently offered 'Murial Harbard' at $300 New Zealand. Colors range from bright yellow, apricot, many shades of rose and lavender, to pale creams and pure white. All pleione flowers have contrasting markings on the lips of the flowers - bright red, pinkish mauve, yellow, brown, and old rose to name a few. Many of the lips are frilled in varying degrees and a few have fragrance. Some of the hybrids reproduce rapidly but many are rather slow. Several domestic growers are offering a limited selection. A word of caution is perhaps due at this time. As with many bulbs, pleiones are being severely over collected in the wild. It is reported that Taiwan exports thousands of wild collected pseudobulbs in Japan each year. At least two large American mail order bulb dealers offer pleiones from Taiwan. This is a real shame as P. formosana is one of the most prolific of any of the species. I would recommend that you seek out only nursery grown plants.

In conclusion I would highly recommend pleiones as companion plants for rhododendrons for gardeners in Zones 7 and milder and possibly into Zone 6. Start with a few of the tougher clones such as 'Blush of Dawn' or 'Oriental Splendor' and build from there. For those in colder climates, try a few in a window ledge or plant room. I am sure you will be glad you did.

Richard Cavender is the owner of Red's Rhodies in Sherwood, Oregon. He is a life member of the ARS Portland Chapter and an associate member of the Tualatin Chapter. He is an avid collector of rhododendrons, especially vireyas, and pleiones. He is happy to hear from others with similar interests.