John is a long standing member at Sheffield, and has been growing these little gems for almost 40 years. He first saw Pleiones in 62/63 when working as a young gardener in Bolton. These were formosana, and were very attractive as well as unusual. One of their major appeals was that they didn’t need heat unlike most orchids. After seeing how easily they grew and multiplied, John took the plunge and bought some formosana ‘Snow White’. These were quite expensive at the time, but have repaid the cost many times over as he still has the stock some 40 years later, and of course they flower every year. They really are plants for sustainable growing
Pleiones were first discovered by Don in 1825, and they were initially classed as Coelogynes, and still remain in that tribe. Generally they are from the high altitude areas east of the Himalayas, across Asia to Taiwan, and grow in dappled wooded areas. They are deciduous, and often suffer freezing temperatures. Plants grow from an annual pseudobulb which then dies to be replaced by a new one. The flowers are produced first and the leaves later. The bulbs have sufficient energy to produce the flowers without watering as they don’t produce roots until the leaves start growing, but dampness is useful to prevent dessication or poor flowers. Ownership of the genus has varied over the years, with neither the RHS or the Alpine Garden Society wanting anything to do with them for many years. They are now RHS, and included within the Sanders hybrid lists.
The end of the year is critical in the cycle for commercial growing. The bulbs and bulbils should be collected, cleaned and sorted into size. The biggest retained for exhibitions are repotted about 2” apart. Clay pots are best for this as they help in cooling. These plants should be kept cold and only warmed up a few weeks prior to a show. Most will be 4-5 weeks, but some will be 6-7 weeks from flowering. A large shop style drink chiller is used to keep plants for this purpose. Shading early in the greenhouse will help to keep them cool and prolong the length of the flowers. The larger non-exhibition bulbs are potted individually for sale, and the smaller ones and bulbils go into trays to grow onto flowering size.
Compost is important, with some variation. The species prefer moss, with some being wood moss, and others sphagnum moss. The hybrids tend to go into a mix of nugget bark with varying amounts of perlite and osmunda.
As the flowers die, the roots and leaves start to grow, and watering/feeding can begin in earnest. Don’t over feed however as this causes leaf tip dieback. John uses Maxicrop (seaweed extract) at a rate of 3 teaspoons per gallon every few weeks. Pure water is used at other times. During the summer, plants will grow outside, often in full sun. Their delicate leaves will attract a few bugs – false spider mites are an issue, and are treated with neem oil, whilst aphids receive a dose of Bug Free. The leaves die back in Autumn, and the cycle begins again. Hybridisation has greatly enhanced the range of Pleiones, although it wasn’t until the 70’s that it began. John has made several, although only 1 is registered (Ruby Wedding). Shantung registered in 1977 (by Dr Harberd in Leeds) was probably the major breakthrough as it was the first to incorporate the yellow forrestii. Mixing yellows with pinks can give rise to various shades in between such as peach etc. Some 5000 seedlings were raised of the cross, with just 16 being retained as named clones. Some of these (Ridgeway/Ducat) attracted prices of £200 per bulb at the time! This hybrid has been used many times with other species and selected hybrids to produce some fine progeny. Using forrestii has also created some very good primary hybrids. John then went through some of the very best hybrid clones explaining the best features of each such as Stephanie Rose, El Pico ‘Kestrel’ is tall, Vesuvius ‘Phoenix’ is vibrant, Krakatoa has good peach colours, Stromboli ‘Fireball’ lasts 5 weeks, San Salvador produces a good yellow line. In the species, formosana album ‘Claire’ is white with a pale yellow throat, limprichtii is very hardy and will grow outdoors, taliensis is tall. forrestii has a good tale to tell, with only 1 bulb remaining in the UK during WW2.
This was in fact a natural hybrid called x confusa (which became a parent of Shantung). Being a hybrid is possibly why it survived… This only became apparent when Roy Lancaster fetched some true forrestii back with him from China. After a few questions, a hearty round of applause was given. Thank you, John. NB. Further info on the species can be found in the May 2008 newsletter. JG