The calanthe offered are the small group of species that are both hardy and near evergreen. There are some 180 different species but only a few are evergreen and even fewer are hardy. This group comes from various areas of the Far East. In particular several are Japanese native species.
In nature they come from a variety of environments but most are mountainous and with a good rainfall. They prefer a soil with a high organic content.
Here they can be grown in pots or in the garden. I use a mix of peat based compost, fine bark and coarse perlite for the plants I grow in pots. This year I have fed some every fortnight with weak Tomorite and others I included slow release fertilizer in the mix. There does not appear to be much difference in quality of growth. In the garden, I add composted bark to the soil to provide the level of organic matter needed. Planting into the garden can be done at a variety of times. Late summer planting enables the root system to develop as the plant settles in, although it is acceptable to plant at other times without problems.
These orchids have pseudo-bulbs that lie just under the soil. In the summer plants begin to produce new growths under the ground and new roots. The buds may remain below the surface or just poke out of the ground in the autumn. If there is frost during the winter the old leaves will be come damaged but I do not cut them off until the spring. To protect the plants in very frosty conditions I apply a 5 cm cover of bark. In late March I cut off all the remaining old leaves. This encourages the plant to start growing. The flower spike emerges from the centre of the new leaves as they grow. The leaves are spear shaped and pleated. Flower spikes are between 25/50 cm tall depending on species and hybrid with various numbers of flowerson each spike. In a good season the flower spike will remain for six weeks or longer. After flowering the leaves fully grow and the plant begins to expand. Potted plants make ideal show plants as growth and flowering time can be controlled to some extent. My show plants are kept in a mini-polytunnel during the winter months with fleece thrown over in severe weather. Some six weeks before I want to exhibit them I will move them into the alpine house and cut off all the old growth. I increase watering at the same time having only allowed the compost to be slightly damp for the winter. If flowering is slower than anticipated I bring them into warmer conditions. Once the flowers are out then they go back into the alpine house to maximise the flowering period. Once flowering is over, plants are put outside for the summer in semi-shade. If plants are used for a long exhibition I leave them in the alpine house until they are fully hardened off as putting them out when temperatures are still low can cause leaf damage through shock. Plants in the garden are somewhat tougher and able to cope with conditions more effectively. All the plants currently offered have been seed raised in Europe and have root systems that fill a 1 1/2 lt pot. All have at least 3 flower buds and some have upt to 10 depending on species or hybrids. Please note that because the plants have been raised in ideal conditions on the continent some do not flower as well in the second year producing more foliage growth than flower buds. This is rectified in year three. I now have plants first purchased late 2012 with 15/20 flower buds for next season. These are all in 5 or 7.5 lt pots.
Customers will usually receive their plants in 1lt pots. What actions should then be taken depends on the time of year. Whilst my stock is kept in cold sheltered conditions plants purchased in the autumn or through the winter should be kept in their pots in a cold greenhouse or sheltered position until the spring. Pots should not be allowed to freeze. Plants purchased in flower or in the early spring may be planted out if conditions are right but protection will be necessary if there are late cold periods in order to allow the owner to enjoy the flowers for a longer period. You could keep the flowering plant in a cold greenhouse until flowering has finished and then plant it out or, if it is going to be kept in a pot put it outside in a shady area and keep moist. Re-pot in the late summer into a 5 lt pot and feed regularly until late autumn.
23/1/16 news. Just been checking my show pots. Alll the plants are in 5 lt pots with a variable mix depending on when they were originally purchased. All the pots were treated with slow release fertilizer last spring but I am unsure that it was really successful as there is still a lot of undesolved "peas" on the surface. All the pots have been under a mini polytunnel I built in late October. There is quite a variablity in growth. Older pots with a high fine bark content did not hold as much moisture whereas those with more peat/perlite in the mix have developed faster. One problem has been the high December temperature which encouraged some of the early hybrids to begin growth. Three days of minus 6C damaged some of this growth because it is rather soft.
My first big show is London at the beginning of April so I have cut off the old leaves from a percentage of plants, thoroughly watered the pots and put them into a warmer environmentto encourage growth. This I will repeat at weekly intervals for the next five weeks. This will provide flowering plants for London, Hardy Orchid Show (where I am giving a talk on growing this genus) and the Harrogate Show.
"7/1/16 got my timing wrong with hybrids that have sieboldii in. They are already in flower. This was a combination of time and the higher temperatures in my conservatory than I would expect.