Semi-rustic orchids to be sheltered from severe frost in regions with harsh winters (temperatures below -10°C).
The young Calanthe shoots appear and fully deploy their leaves as of April. Their flowering is optimal in May. Following the flowering, the foliage, fairly persistent, remains green at least until October before fading and disappearing completely. Calanthes then go into their winter dormancy. The faded leaves can be cut, preserving a stem height of 5 cm. Certain species present persistent foliage all year round.
Over the years and following the successive growth and dormancy cycles, Calanthe not only become stronger but also multiply, thanks to the annual appearance of new shoots.
Calanthe are semi-rustic and can withstand a minimal temperature of -10°C. You are advised, at least in regions with harsh winters, to cultivate them in a jardinière in order to shelter them from severe frost during the winter.
During the winter, the plant persists in pseudobulb form.
Calanthe require well-aired and drained soil. Use of some compost rich in humus and pine bark is recommended. In the garden, they can be cultivated under the same conditions as hostas or ferns.
Particularly suitable for being grown in pots, they appreciate a well-drained substrate. It is necessary to avoid an overly strong retention of watering water, which would encourage rot. You are therefore advised to put balls of Argex or pieces of frigolite at the bottom of the pot in order to ensure good drainage.
Be sure to select a large enough pot (minimum diameter 30-40cm) in order to avoid impeding the development of the new peripheral shoots that will appear during the following year.
The ideal site will be sunny or semi-shaded.
Fertilisation and Pesticide Treatments
In summer, a contribution of manure every fortnight is necessary. A horticultural manure of the NPK 20-20-20 variety can be used.
If necessary, protect the tender young shoots against slugs, during their emergence in the spring.