The culture sheet in its original form was provided to the Queensland Orchid Society by the guest speaker, Sam Cowie, who presented a programme on Oncidiums during the GENERAL MEETING conducted on Monday, 9 June 2014 at the Red Hill Community Sports Centre, 22 Fulcher Road, Red Hill, QLD 4059, AUSTRALIA. The members were able to buy well-grown, sizeable plants from Sam during the supper break.
Furthermore, below the culture sheet are multipronged discussions on various growth habits of Oncidium intergeneric orchids, air, temperature, light, watering, root systems, potting mix, pots and fertilizers.
Oncidium Intergeneric (Dancing Lady) Orchids
Oncidium Intergenerics are a large group of orchids bred from several families (genus) in the group Oncidium, or dancing lady orchids. This group also contains the Miltoniopsis (Pansy Orchids), and Brassia (Spider Orchids). This group of orchids originates from Central and South America and is tolerant of a wide range of conditions, but to maintain and grow your orchid we have put together some general pointers to help you.
The trick to growing your orchid is to maintain regular moisture so that the bulbs are nice and full. Water regularly to keep moist and allow them to drain off excess water, but don’t let them sit in water. A general rule of thumb is to water once every 3 to 4 days when kept inside, or every 2 days when outside. In the heat of summer this maybe increased to everyday (outside) or in winter every 3 to 7 days depending on the weather (outside).
Your orchid likes to have humidity around their root system, so another trick when growing outside is to sit their pot inside a larger pot, eg a terracotta pot, that has a layer of gravel in the bottom, this will keep the roots cooler and humidity higher. As a general rule Miltoniopsis (Milt.) and Odontonia (Odtna.) varieties will prefer not to dry out at all, so water regularly.
Whilst your orchid is in flower you may keep it inside to enjoy. When it has finished flowering you may then move it outdoors. The orchid you have purchased with this culture sheet has been grown in SE Queensland under 50% shadecloth or white Solarweave, not a climate controlled greenhouse. Therefore you only need to provide a sheltered position with approximately 50% shade as the basic growing condition. Your dancing lady orchids will tolerate temperatures from 2 to 38 degrees celcius, but have been known to tolerate extremes outside of this range.
If you don’t have a shade house, your orchid will grow on a sunny verandah out of direct sunlight, or in the garden where it is shaded by trees. Some varieties in the Miltassia (Mtssa.), Brassia (Brs.) and Oncidium (Onc.) will happily grow as epiphytes on the trunks of trees such as Frangipanni, where they are shaded in summer and receive full sun in winter when the Frangipanni loses its leaves.
As a general rule of thumb, they will prefer more shade during the summer months and less shade during the winter months. Some types such as Miltonia (Milt.) and Odontonia (Odtna.) will prefer a shadier spot than other types like Brassia and Oncidium.
The easiest way to fertilise your orchid is to to apply a slow release (eg Nutricote or Osmocote) once a year in spring at the manufacturers recommended rate. Regular supplementary applications of liquid fertiliser will help, so ask your local garden centre about specialist orchid fertilisers.
Repotting maybe done most of the year when the plant is actively growing roots (look for the little green root tips). The best time, which will vary between each variety, is just after flowering and as the plant is producing new bulb growths. Dancing Lady orchids prefer to fill out their pot prior to repotting, and if potted up do so into a pot only a little bigger than the old one. For example if your plant is in a 105mm pot, go up to only a 130 or 140mm pot. Well drained squat pots are best.
The preferred potting mix is either a medium to coarse bark or a medium coco husk chip (CHC) and coarse perlite mix. In general the potting mix should be open and drain well whilst holding a limited amount of water. After repotting sprinkle a teaspoon of Gypsum and half a teaspoon of Dolomite over the potting mix to add calcium and counter any excessive acidity, then add a slow release fertiliser at the manufacturers recommended rate.
If your orchid starts to grow roots over the top of the pot don’t worry, most are epiphytic in their natural habitat, so roots will grow out of the pot in the open air if your growing conditions are right.
Pests and Diseases
The first major pest of Dancing Lady orchids is slugs and snails, which will eat the roots and flower spikes. A few pellets of snail bait placed in the pot will control these, or grow your plant up and away from where slugs and snails can get to them. The other major pest for flower spikes is caterpillars, so keep an eye out and remove when seen. Otherwise a suitable insecticide maybe purchased from your local garden centre.
Other occasional pests are scale, mealy bugs and aphids, which may all be controlled by a suitable botanical oil spray and/or with a recommended insecticide. Be careful to read the instructions and don’t apply on hot days or during hot weather.
Occasionally your orchid will get fungal or bacterial spots on its leaves, which maybe controlled with a suitable fungicide available from your local garden centre. Some varieties prefer to be grown under cover to avoid wet foliage and continued damp potting mix from lengthy rain periods that will increase the occurrence of leaf spots. Most are not threatening to the life of your plant, but do detract from the overall appearance. Some varieties such as Onc. Space Race will get a little black spot on the leaf during cold weather.
Dancing Lady orchids will flower at various times of the year, so check your local supplier regularly for the seasons variety. Some will flower even twice or three times a year, whereas some will flower once a year during a specific time. When your plant starts to flower bring it in under cover and avoid getting water on the flower spike in the last weeks prior to flowering.
For further information on growing your Oncidium Intergeneric orchid, visit your local orchid society shows or meetings, where the sharing of growing hints, tips and successes will help you grow and enjoy your orchid for a long time.
© Copyright Leaf & Limb, QLD, Australia (Version 1.2) 2014. This culture sheet provides general information and may not cover every growing/pest/disease/potting mix/flowering situation that may occur.
Gallery of Oncidium Intergeneric (Dancing Lady) Orchids
Barbara Haywood 8 September 2014: I was talking to a friend yesterday about oncidinae and what a variable group of orchids are within this genus. We were talking about the varoius growth habits root systems and what potting mix, pot types were most applicable or suited to the various ones. What are some of other peoples thoughts and ideas on this?
Richard Cooper Fresh moving air appears essential (use fans, if necessary) – hang plants about 500mm below 50% shadecloth for better air movement. Protect from frosts (though I don’t get them here). Grow in a sunny position. My mix is basically – medium bark, coarse perlite, 8-10mm river gravel, charcoal, a handfull of 2 of cocopeat – keep your mix fresh so repot as new growth appears and lightly topdress with Dynamic Lifter or similar. Water lots during summer and allow a wet/dry cycle at other times. Fertilise weekly; flush between applications. 8 September 2014 at 19:00 · Unlike · 4
Barbara Haywood Thank you very interesting culture Richard, I bench most of my intergenerics and use only spagnum moss. The pure oncidiums I grow in a similar mix to yours just minus the peat as we get ripper frost down to -4°C we heat to about 8°C at bench height. And we do the same with the watering and fetilizing. I only repot when a new growth reaches 3 inches high this seems to be the optimum time. I was told this years ago by a big Odontoglossum grower and hybridizer. Yes we have fans going most of the time and a fogging sytem we use in the summer as the hothouse goes over 50°C We had 16 days in a row outside temperature of over 40°C last summer. We 70% white shade cloth behind clear polycarbonate sheeting on the hothouse, with an extra layer of 70% shade cloth over the top and down the north wall in summer. We grow in pretty extreme conditions here. 8 September 2014 at 19:24 · Unlike · 3
Paul Slattery I’ve been potting my plants into hydroleca (expanded clay pellets) and using a reservoir in the base of the pots to control the water supply. I’m using plastic cups for the smaller plants and buckets for my big Brassia. I’ve had them in this stuff for over a year now and they seem happy. 9 September 2014 at 17:15 · Unlike · 2
Paul Slattery It’s more like balls of scoria. I’ve been using it for my Paphs for about 4 years now, with good results. http://www.goldlabel.nl/91/Hydrocorn.aspxGold Label Hydrocorn (clay pebbles) are manufactured using a mix of the best quality pure clays and are baked…
K-w SoundEagle Hydroleca (expanded clay pellets) and other similar materials are frequently used as the staple in hydroponics. Here are some examples from a post that I published earlier at https://queenslandorchid.wordpress.com/…/self-watering…/.
Barbara Haywood Yes thank you K.W I may look at this in the future. I use the sphagnum moss because these particullar group of orchids respond to it better in my conditions, seem to keep the roots in better condition , maybe cooler in our summer heat. I think the Oncidiums like the wet dry cycle a little more so I use a bark mix, seems to work the best for our temperstures. 10 September 2014 at 10:45 · Unlike · 1
Richard Cooper KW, I am not a chemist but as I understand the process, plants need nutrients (NPK and micro-nutrients) to grow and to absorb the nutrients they are converted to ions in order for the plant to absorb them. I use tap water which, in this area, is pretty good, it still contains chemicals added by the local water authorities, i.e. extra ions. The various ions react with each other to form salts. There is a school of thought that considers watering/flushing up to 12 hours before applying fertilizer allows orchid roots to better take the nutrients up. In addition, some of the ions (esp. nitrogen) are taken up by the mix (esp. bark) and by micro-organisms in the mix. These build over time and can damage the roots. You may see evidence of this around the holes at the bottom of pots (a white residue). Another view is that flushing reduces the speed and extent of that residue build-up and thus minimises root damage. 10 September 2014 at 19:01 · Unlike · 1
Paul Slattery You are right, Richard. Once a fertiliser salt is dissolved it is in the ionic form and so is available for plants to absorb. Plants don’t really care what form the minerals are in as long as they are able to absorb them, they can usually alter them to suit their purposes. Nitrogen fertiliser is absorbed by the micro-organisms that decompose bark, causing ‘nitrogen drawdown’ in the mix. This is usually only a temporary thing, but can last long enough to cause a deficiency in the plants. The white residue you find around the holes of your pots and on the surface of hydroponic media is usually insoluble so has no effect on the plants, it is merely a waste of a tiny amount of fertiliser. The substance in question would normally be calcium sulphate or calcium phosphate. 10 September 2014 at 19:11 · Unlike · 1
Paul Slattery Flushing the mix is still a good idea, though. Is is possible for the fertiliser salts (ingredients) to become quite concentrated in the mix, especially when the plants are only taking up the water because they are not actively growing much. They leave the fertiliser behind which can build up to levels that can damage the roots. If the concentration of the solution outside the roots gets too high (hypertonic) it will stop the roots taking up water and kill the cells. Flushing with plain water is not necessary, using plenty of fresh fert solution is fine. Sometimes the shock of using plain water can cause more damage if things have been allowed to get bad. 10 September 2014 at 19:19 · Unlike · 1
Barbara Haywood Yes I can see what you are both refering to Paul and Richard. The key in my opinioin to fetilizing is to do it only when the root tips are actively growing, otherwise its a waste of fetilizer. I flush between fertilizing on a regular basis thus I do not have these build ups on my pots, but have experienced it in the past with high nitrogen fetilizers. Now I use lower nitrogen fertilizer aprox 2 to 3 times per week at 1/4 strength, and no problems. As I said only when root tips are active. 10 September 2014 at 19:42 · Unlike · 2
- Dancing Ladies: Oncidiums and Their Relatives (Orchids) (what-when-how.com)
- The Desirable Traits for Oncidium and Its Intergeneric Orchids (icogo.org)
- Oncidium Intergeneric Hybrids (glasshouseorchids.com.au)
- Oncidium Orchids (bribieislandorchidsociety.com)
- Oncidium Orchid Growing (bribieislandorchidsociety.com)
- Bark Products from New Zealand and South Australia for Growing Orchids in Australia (queenslandorchid.wordpress.com)
- ONCIDIINAE (ORCHIDACEAE) (flmnh.ufl.edu)
- Phylogenetics of Maxillarieae: Oncidiinae (Orchidaceae) (flmnh.ufl.edu)