Odontoglossum Alliance orchids include Odontoglossum, Oncidium and related genera. This guide explains how to grow them in Orchiata bark, including grade selection, potting, watering, humidity, temperature, light, fertiliser and troubleshooting.
Growing Odontoglossum Alliance orchids in Orchiata
Odontoglossum Alliance orchids are naturally varied. Odontoglossum are usually found at higher altitudes and prefer cooler conditions, while Oncidiums are generally from lower altitudes and warmer areas.
The main growing aim is to use a media that gives good root contact, good air movement and good drainage. Bark products have long been preferred for larger plants in this group.
Quick starting point: Odontoglossum and Oncidium do not like being dried out too hard. Let the media dry sufficiently between watering, but do not let the pot dry 100%.
Odontoglossum vs Oncidium growing conditions
These orchids are related, but temperature and light needs can differ depending on altitude and plant type.
Odontoglossum
Usually cooler-growing, high-altitude orchids. They generally prefer cooler nights and lower light than many Oncidiums.
Oncidium
Generally warmer-growing and more tolerant of a wider range of media and conditions. Yellow cut-flower types can be faster growers.
Equitant Oncidium
Often need higher light, higher temperatures, excellent drainage and quicker drying between watering.
Choosing the right pot
A range of pot types can be used. Young plants may be started in cell trays, while larger plants are commonly grown in standard coloured plastic pots.
Do not overpot
These orchids prefer not to be overpotted. Choose a pot that allows enough room for one or two more bulbs to form.
Allow good drainage
Drainage must be very good, especially for Equitant and thick-leafed Oncidium types.
Pot with growth direction in mind
Place the oldest bulb close to the side of the pot, with newer growth pointing toward the centre.
Odontoglossum potting stages
Odontoglossum Alliance orchids are commonly grown in a simple 3-step potting system for potted plants and export.
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Orchiata grades for Odontoglossum and Oncidium
The official guide recommends different Orchiata grades depending on plant stage, pot size, climate and whether the plant is closer to Odontoglossum or Oncidium in its growing habits.
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Important: Although these orchids have pseudobulbs, the guide notes they can suffer greatly if dried out too much.
Approximate Orchiata required when repotting
These figures are from the official guide and are useful when planning media volume by pot size.
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Repotting timing and spacing
Repotting time depends on climate and variety. Odontoglossum and Oncidium grow reasonably quickly and can grow year-round, although winter growth may be slower.
Plants started in 1.5–2 inch pots are usually transplanted once they have two well-developed leaves and roots are filling the pot. This may be around 3–5 months after initial potting. They then move into 3 inch pots for around 6–8 months, or until the pseudobulb starts to develop fully.
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The official guide lists total time at approximately 56–72 weeks.
Flower spike tip: When spiking occurs, the guide recommends staking flowers early to keep them uniform and facing spikes the same way because they bend toward the light.
Humidity
Humidity is important for Odontoglossum Alliance orchids because their natural environments are often misty. Higher humidity should always be matched with good air movement.
General humidity
Odontoglossum and Oncidium prefer humidity levels between 55–75%.
Higher humidity
Humidity of 60–80% requires good air movement, especially in cooler months.
Lower humidity
They can tolerate humidity down to 40%, which can be supported with morning and evening misting.
Temperature
Temperature is important for both growth and flowering. Altitude largely defines the preferred range, with Odontoglossum needing cooler conditions and Oncidium handling warmer conditions.
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Flowering note: A slight winter temperature drop for 4–6 weeks can help encourage flowering, but pseudobulbs must be properly mature before flowering can occur.
Light requirements
Odontoglossum generally require less light than Oncidium, although both are commonly grown under dappled shade.
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During winter, shade can often be reduced to allow higher light, provided temperatures are cooler and air movement is increased.
Fertiliser regime
Odontoglossum Alliance orchids grow for much of the year, so regular feeding is important. Both liquid feed and controlled-release fertilisers can be used, depending on plant type and pot size.
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Fertiliser note: The guide recommends granular fertiliser only for Oncidium, as true Odontoglossum can be very sensitive.
Watering Odontoglossum and Oncidium in Orchiata
Odontoglossum and Oncidium need to dry sufficiently between irrigations, but should not dry out completely. Their pseudobulbs store water and food, and shrivelling bulbs can indicate stress.
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Do not dry completely
The guide says 60–70% dry is acceptable, but the pot should not be allowed to dry 100%.
Equitant Oncidium
These need to dry out quickly and completely between waterings or they may suffer from rot.
Yellow Oncidium types
Some yellow pot-plant Oncidiums can grow faster if kept wetter, as they have large bulbs and extensive root systems.
Watering tip: Lift or weigh pots to learn when they need watering. Over time, you will learn the weight of a pot that is ready for irrigation.
Testing EC, pH and water quality
The official guide recommends testing media every 4–5 weeks to check for salt build-up. With Orchiata, flushing is not required at every irrigation, but regular checking is still useful.
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The guide recommends the pour-through technique using a medium-to-moist pot, clean fertiliser-free irrigation water and a clean collection container.
Growing in warmer-than-ideal conditions
If temperatures are higher than desired, the official guide notes that terracotta pots can be used with a finer grade of Orchiata, such as Classic or Precision.
Why this helps: The aim is to help keep the root system cooler. In many orchids, the root system is the most vulnerable part of the plant when temperatures are above the ideal range.
Troubleshooting Odontoglossum and Oncidium in Orchiata
Common issues are usually linked to excess moisture, water quality, temperature, light, airflow or pests.
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Beneficial organisms: The guide notes that Orchiata is not sterilised media. It contains natural beneficial organisms that may aid against pathogenic species.
Odontoglossum and Oncidium in Orchiata FAQs
What Orchiata grade is best for Odontoglossum?
For initial planting, the official guide recommends Orchiata Precision. For second potting, Classic is recommended. For final potting in moderate climates, Power is recommended for Odontoglossum.
What Orchiata grade is best for Oncidium?
Oncidiums can often be grown in Classic, especially faster-growing yellow cut-flower types. In humid climates, Power is usually sufficient.
Should Odontoglossum and Oncidium dry out completely?
No. The guide says they should dry sufficiently between watering, but not dry out 100%. Around 60–70% dry is acceptable.
What temperature do Odontoglossum orchids prefer?
The guide lists Odontoglossum at 10–16°C at night and 18–24°C during the day. They can tolerate down to 7°C in winter.
What temperature do Oncidiums prefer?
The guide lists Oncidiums at 12–18°C at night and 24–27°C during the day. They should be kept above 10°C in winter.
How often should I water Odontoglossum and Oncidium?
It depends on pot size and climate. As a guide, 4–5 inch pots may need watering every 5–7 days in warm climates and every 10–14 days in cool climates.
Can I use controlled-release fertiliser?
Controlled-release fertiliser can be used for some potted plants, especially Oncidium. The guide notes true Odontoglossum can be sensitive, so liquid feeding may be safer for those plants.
Shop Orchiata for Odontoglossum and Oncidium
These are the Orchiata grades most relevant to Odontoglossum Alliance orchids based on the official guide.
Orchiata Precision
3–6 mm bark. Recommended for initial planting from flask into small pots or cell trays.
Shop Orchiata Precision
Orchiata Classic
6–9 mm bark. Recommended for second potting and useful for Oncidium and faster-growing types.
Shop Orchiata Classic
Orchiata Power
9–12 mm bark. Recommended for final potting Odontoglossum in moderate climates and useful in humid conditions.
Shop Orchiata Power
More Orchiata resources
This Odontoglossum guide is part of our Orchiata growing guide series. For a broader overview, visit the main Orchiata growing guide. For production, quality assurance, grades and technical product information, visit the Orchiata technical guide.
