Thank you to John McCarthy for this article which featured in our Spring 2015 Newsletter.
Pleiones are very colourful, and flower in Spring to early Summer for quite extended periods. For showing purposes, they are acceptable in a wide range of classes and are not required to be displayed as a single plant. Many flowering sized specimens of a single clone can be crammed into a specified pan size to dazzling effect. I don’t crave success in winning prizes and rarely enter formal shows, but I grow Pleiones purely for my own and friends’ pleasure. The fact that many are relatively easy to cultivate and propagate is a bonus – rareness and difficulty do not impress me as much as they used to. The only real challenge is the need to provide protection for the resting pseudo bulbs from freezing conditions during Winter dormancy . They should need little or no water from October to March, or until signs of new growth appears in early Spring.
Pleiones have been classed as bulbs, corms and tubers but currently are described as pseudo bulbs. They are in fact terrestrial orchids and are found in the wild sitting in bark and leaf litter containing little nutrition – this is derived from abundant water passing through the porous growing medium.
These conditions are emulated in cultivation by growing in shallow pots using loam free compost leaving around one third of each bulb exposed above the mixture of crushed bark and coarse peat, with small additions of perlite for moisture retention. This should contain no added nutrients, but regular liquid feeding is needed after flowering when leaves take over, the old bulbs shrivel and new ones appear. These must develop to full size to provide flowers for next year. Once dormant the old roots will die and by January can be cut back to about 2 – 3 cm when repotting. This must be done before new roots form, as the disturbance will likely kill them and the plant. The re-potted plants will not need water, unless bone dry – then water sparingly to stimulate new root growth. Once flowering starts, regular watering will be needed. I have found that the hard tap water here is unsuitable and use rainwater as long as it’s available.
Pleiones are relatively pest resistant ,but the emerging flowers will be vulnerable to attack by aphids so an occasional spray will usually be needed then.
Propagation for the amateur is easy and consists of division during dormancy and as leaves die a careful search will reveal plenty of bulblets which fall or can be brushed off the withered old bulbs. These can be potted up and kept barely moist in compost over Winter. By Spring a good proportion will be found to have rooted. They will take 2 – 3 years to reach flowering size but will be true clones of the parent plant. Be warned – you can end up having more Pleiones than you bargained for!
Most plant sales will offer a few of the easiest clones. If you want more scope, I have found the best source is Ian Butterfield’s ‘Yaffler’ nursery at: Harvest Hill, Bourne End, Bucks, SL8 5JJ, Tel: 01628 525455. He will send you his catalogue. This will describe over 80 species and hybrids for sale. It also gives a much more detailed and authoritative account of their culture in the UK.
The AGS seed list usually includes some Pleiones in the Bulbils, Cormlets etc. section. These will require patient growing on for 2 – 3 years to flower but will have cost nothing and require little effort. They are best left alone and not re-potted, kept just moist and given the occasional liquid feed when in leaf, until they mature.
If you are not disposed to the chore of division and repotting each year, the easier Pleiones can be left undisturbed for years and only moved on as a growing clump into progressively larger containers. Provided they are fed when in leaf and protected from freezing, this can go on for years until the colony becomes too big and heavy to handle. Pleiones perform best when slightly pot bound.
Finally, this is a recipe for enjoyment. If you are a compulsive collector, as I have been at times, Pleiones can become an obsession. New ‘must have’ varieties are being introduced by the breeders all the time and this can become an expensive and time-consuming hobby. They are not hardy garden plants. The AGS admits them to shows but this doesn’t make them traditional Rock Garden plants. However, they are exotic and beautiful and a small, varied collection will give much pleasure without much effort or expense.