The Odontoglossums were first imported into England in 1815, but not flowered until 1835. Since then knowledge of its culture, and related genera, has moved forward.
Odontoglossums are native to South America in an area spanning the equator north and south by 15° latitude. The cooler growing species are found growing in the Andes of South America in Ecuador, Venezuela and Peru with the largest number found in Colombia. In these areas a fog-like mist occurs at the 2000 metre level, and rarely disappears. The humidity of the region above this level is kept constantly high and is often referred to as "cloud-forest".
Simply put, the Odontoglossums prefer similar growing conditions to, but less light than, Cymbidium and Zygopetalum and would feel right at home with Masdevallia. Like many orchids they will tolerate some extremes if other conditions are adjusted to create a natural balance. eg warmer climates- reduce light further, increase humidity and use more open composts when you may need to water overhead more often.
Ideal growing temperature is around 12°C with regular temperatures below 7°C or above 35°C to be avoided. The higher night temperatures are acceptable, however, they slow growth and shorten flower life.
Should be maintained at 50% for superior results. To increase humidity spray the plants with a misting system. The evaporative cooler employed to create air movement and under bench misters are acceptable alternatives. Water controls humidity and keeps composts damp. Water heavily and more often in warmer weather. How often you water will depend on your conditions. Open compost will allow you to water or mist daily in warm weather and weekly in the colder months. Never allow plants to become completely dry nor remain sour and soggy.
Air Movement & Ventilation
This is most important. All Odontoglossums and their hybrids appreciate a high humidity, they are prone to fungal attack. They respond favourably to ventilation. Operating fans constantly to provide good air movement is beneficial, and reduces the risk of bacterial and fungal infections. They can be prone to this particularly at night with spotting of leaves and blooms. The phrase "buoyant but not stagnant" sums it up. A green house that allows a free flow of air, and a fan that can be used, is ideal
Light levels tolerated by Odontoglossums range from 500 up to 4000 foot candles. Maintain mature plants near the middle of this range, seedlings at the lower level. Quality cultural practices enable Odontoglossums to tolerate and profit from higher amounts of light. Leaf colour is an indicator of light quality. If the leaf is dark green then the plant can benefit from greater light. A redish cast indicates that there is too much light and the plant should be moved. However, to improve flowering and strengthen colour in blooms with darker shades more light can be used. White and lighter coloured shades are improved in their appearance if bloomed in more shade
Almost all Odontoglossum specialists use plastic pots because these lightweight containers will not hold fertiliser salts. Plastic pots are easier to handle and keep clean.
Most growers rely on a fir-bark mixture incorporating 6mm to 20mm bark chips. Combine about 3 parts bark to 1 part pearlite. The mixture is easiest to work when dry, because it quickly fills the voids around the roots. This is not the only successful medium, some individuals supplement the basic mix with several additives, including sphagnum moss, hoof & horn meal (or "Feathers & Fins"), peat moss and cow manure. The availability of New Zealand sphagnum moss has prompted some growers to try this spongy medium with mixed success. (One thing should be said about sphagnum moss, it does not respond well to artificial fertilisers, use only organic fertilisers for best results) See what most of your collection has and what your watering program dictates.
Repotting should be done every 12 to 24 months when the new growths are 50 to 75mm tall, in early spring or autumn, and green root tips are evident. Dampen or soak the new mix first and either crock the bottom of the pot with larger bark or styrene to increase drainage and aeration. Plants should not be "over-potted", plant vigour may dictate that a plant an orchid be potted on, or heavy watering and fertiliser in warmer climates lead to more rapid breakdown of the mix. Position the plant so that the bottom of the pseudobulb is approximately 6mm from the top of the pot. Fill with the mixture so that it reaches the base of the pseudobulb and tamp lightly with your fingers. Water should flow through easily.
Watering and Feeding
Never allow plants to dry completely or be in swamp-like conditions. A schedule depends on the type of container and its size, medium, plant and environment in which the Odontoglossum sits. Misting daily and watering the pot weekly is adequate. Apply a week fertiliser solution every 2 weeks during the main growing season and monthly thereafter. Alternate between an organic and non-organic formula, and mix at one half the recommended strength.
Odontoglossums are susceptible to scale, mealybug, aphid, red spider and spider mite. It is best to remove these culprits or wipe them away with a cloth dampened in soapy water. Odontoglossums may fall prey to slugs and bush snails. The latter causes minor root damage, but the slugs can severely damage inflorescences and flowers. Cleanliness and vigilance along with slug poisons are the solution. Viruses can also infect Odontoglossums and, unfortunately, there is no cure. However, sterilising cutting instruments before use on different plants will reduce the risk of contamination.
Begin with Odontoglossums that are flowering or about to bloom. This will enable you to develop your cultural conditions with strong stock. Experiment with Odontioda, Wilsonara, Odontonia and Odontocidium if you cannot provide the lower night and day temperatures required for pure Odontoglossums.
- Odontoglossum Hybrids & related genera
- BurragearaOncidium x Cochlioda x Miltonia x Odontoglossum
- LageraraOdontoglossum x Cochlioda
- MaclellanaraOncidium x Brassia x Ondontoglossum
- OdontiodaOdontoglossum x Cochlioda
- OdontoniaOdontoglossum x Miltonia
- VuystekearaOdontoglossum x Miltonia x Cochlioda
- WilsonaraOncidium x Cochlioda x Odontoglossum
- OdontocidiumOncidium x Odontoglossum