This easy to grow genus of terrestrial orchid is a native of China, Japan and associated Asiatic areas and islands. There are a small number of species available and over the last twenty years about twenty hybrids have been produced and registered. It was one of the first orchids to be cultivated in the United Kingdom with references as far back as 1794.Whilst the genus is relatively hardy when growing, because the pseudo-bulb is only just under the surface it cannot tolerate any heavy frost unless well protected. Because of this many people will grow the orchid in a pot left outside for the summer and then put into a frost free environment in the winter.
All are typical perennials commencing growth in the spring from the buds that were generated in the previous summer and autumn. The plant will produce a number of spear shaped ribbed leaves from each section of pseudo-bulb in the spring and the flower spike will emerge from the centre in June/July. The basal portion of the leaf encircles the stem and the sharp pointed leaves are held fairly stiffly.
Depending on species the flower spike is from 20 to 40 cm tall and usually has 4 to 10 flowers on each spike. The flowers open from the bottom, with 3 or 4 out at any time and in a good season the plant will be in flower for about a month. Each flower is typically orchid like with five spreading sepals and petals and a furrowed lower lip that is often a different colour to the others. Size depends on the parentage. The largest can be up to 8 cm across.
Having flowered, the pseudo-bud will begin the process of producing new buds and new roots adjacent to the buds which develop at the end of the new “horns”. It is at this time that the clumps should be divided. It is easy to break the pseudo-bulbs apart by hand. Doing this at this time ensures that new buds and new roots are not damaged as they would be if this task was done in the autumn or winter.
There are various opinions as to the best place to grow the genus. The best plants I have seen were all in full sun rather than the semi-shade often suggested. The pseudo-bulbs seem to appreciate the warmer soil and appear to flower more readily.
Alternatively, Bletilla make very good pot plants for a patio. However, in this situation it will become obvious after a few years that the pseudo-bulb produces new buds on the outside each summer and eventually the centre bulbs become woody and are effectively dead and need removing.
The best time to plant pseudo-bulbs is in the spring before growth commences. Choose a site where the plant will get a good length of daylight and where the soil will not dry out or stay water logged in the winter. If the soil is heavy clay then add grit and fine bark to open it up. Dig a hole 15 cm deep; hold the pseudo-bulb in the hole at a depth of 3 cm with the roots spread and then fill the hole with mix. If the area is subject too late frosts then cover the plant with 5 cm mulch so the new growth does not get frosted.
Bletillas will respond to good feeding throughout the season, using a high potash liquid fertilizer at ¼ normal dilution.
If the plant is in the garden it is important to put a deep mulch over the plant in October. In areas of high winter rainfall a pot over the clump may also be useful.
Plants in pots should be put in a cold greenhouse for the winter and not allowed to get frosted. Nor should the pot be allowed to dry out completely. It is important to allow the plants to be reasonably cold during the winter as this helps with flower production.
Plants are usually sent out potted. If purchased in the autumn your plants should be kept in a frost free environment for the winter. This could be a greenhouse or even in the garage as the plant will be fully dormant. Do not keep in a warm environment as the plant will start growing far too early. Spring purchases that have just commenced growth could be planted out provided the weather is suitable. If only buds have appeared than cover them with dry mulch to allow additional protection for a couple of weeks. Plants bought in growth can be planted out without problems provided they are adequately watered for the first few weeks.
news 24/1/16 This winter is causing some headaches for me. I have some 50 four lt pots of both show and sales stock. Older pots are in the mainn still fully dormant irrespective of whether the pot remains damp or has dried out. However, the large pots of the five hybrids I bought in the summer and did not divide have reacted in two different ways. As I would expect those pots that are damp now have growth anything from 3 cm to 15 cm all ready; whereas, those that are drier have not moved. I can make use of this. I will move a small number of pots into warmth in late February so I can use them at London. If you visit the London Orchid Show you can see if I have got my timing right.