Pleione
Semi-rustic orchids have to be sheltered from severe frost in regions with harsh winters (temperatures below -10°C).
Growth Phase
The young Pleione shoots develop in March/April and flower in the spring. After flowering, the plant continues to develop its foliage and to mature its bulbs. Come the autumn, Pleiones go into their winter dormancy, and the leaves yellow, fade and disappear. Over the years, the bulbs divide to form increasingly large masses.
Winter Dormancy
During the winter, the plant is at total rest and only the bulb persists. Keep it dry and sheltered from severe frost during the entire winter period until the resumption of growth at the end of the winter.
At the beginning of spring, when the bulbs start to germinate, moisten the substrate very slightly.
The old desiccated pseudobulbs can be removed.
Planting
Tolerating only light frost (-10°C), these orchids will not be able to be kept in the garden in regions with harsh winters. We recommend, at least in those regions, to cultivate them in a “jardinière” in order to winter them away from strong frost.
Be sure however to select a large enough pot (diameter 20cm) in order to avoid impeding the development of the new peripheral bulbs.
The bulbs should not be buried in the substrate but planted so that a third of their size protrudes from the compost.
Once the growth has begun, never depot the plant: Pleiones are unable to reform broken roots. The bulbs therefore should not be disturbed as from the moment when the shoots start to germinate.
These orchids are highly tolerant with regard to their substrate. You can keep them in peat-based substrates or in mixtures of bark chippings, lava stone (vulca) and compost.
Exposure
The ideal exposure will be semi-shaded. A site in the sun is not excluded but then take care to keep the substrate wet as from the spring and during the entire summer. In order to prevent the substrate from drying too quickly during the growth period, you can cover it with a layer of wood foam.
Fertilisation and Pesticide Treatments
Pleiones are relatively greedy for manure during the growth period. When the leaves are developing, fertilise the plant with a horticultural manure of the NPK 15-15-15 variety. Do not fertilise when the plant has no leaves.
If necessary, protect the tender young shoots against slugs, during their emergence.