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With the recent changes in nomenclature eradicating the genus ODONTOGLOSSUM (and consequently many hydrid genera) some confusion about the correct names for some orchids is inevitable. As many books, journals, catalogues culture leaflets etc still refer to ‘Odontoglossum’ and the hybrid genera including it, they are retained here whilst the transition takes its course.
The heading ‘Odontoglossum Types’ refers to a complex group of plants which is the result of mixing many different genera (such as Odontoglossum, Miltonia, Brassia, Oncidium) to give us an unrivalled range of colours and colour combinations, as well as varied flower shapes and sizes, often known collectively as the “Butterfly Orchids”. The group includes Odontioda, Wilsonara, Vuylstekeara, Odontonia, Beallara, Burrageara - to name but a few. Their origins can be traced back to Central and South America, where they are found at high elevations, which accounts for their love of cool, moist conditions. The creation of these multi-generic hybrids has resulted in plants that will tolerate warmer conditions, with the result that they can be grown quite successfully in the home, as well as in greenhouses.
They will enjoy full light in the darker days of winter, ie. south facing window.
In summer shade from direct sunlight or place in west, east or north facing window.
WATERING & FEEDING
A good watering once a week is usually quite sufficient. However, when conditions are warmer and the plants are drying out more rapidly, it might be necessary to increase this. The old rule still applies: “If in doubt, DON’T”. The plants in this group have ‘bulbs’ so have the ability to withstand short periods of dryness. If the new shoot appears concertina-like, it is a sign of lack of water – either because you have underwatered, or the plant has a poor root system that cannot take up enough water.
Feed every second or third watering in spring /summer and once a month in autumn /winter. A high potash feed is beneficial.
This group of plants has a growth cycle in which a new shoot appears from the base of the last ‘bulb’; which elongates as it grows, and then fattens to form the new ‘bulb’, when it will normally produce a flower spike or stem.
Potting is best undertaken when the new shoot is approx. 4 -5cm long, as this is when new roots are being formed. As the roots on this group of orchids are thin (compared to Phalaenopsis) it is important not to overpot, and to use a good quality orchid compost that combines the qualities of free drainage and moisture retention. Repot every other year or when there is not enough space in the pot for the new growth to develop. Remember a plant that has a good root system that dominates the compost, will be a successful plant.
The flowers on these wonderful plants will usually last 6-8 weeks if the conditions are cool and fresh. When your plants are in growth mode (have finished flowering and showing a new shoot) place them in a cool room until they come back into spike.
After the flowers have finished the old stem can be cut back to the leaf axil to be tidy, as it will not reflower from it. New stems will appear as the new bulb matures.
Culture information taken from the Growers and Buyers Guide to Orchids in the UK – 2013 (Golden Guide).
Photographs supplied by S. Pask unless stated.