Light is a very important factor in getting Cymbidium orchids to flower. Abundant light without the risk of leaf burn will give you the best chance of a 'good' flowering. At Royale Orchids we grow our mature plants under 50% shadecloth throughout the year. This amount of light causes the leaves to yellow slightly during the Summer period; they will regain a deeper green colour as the weather cools. Space your plants so as to allow for good light penetration to the bulbs and base of the plant. This will also provide good air movement around the plants, which will reduce many fungal / pest problems.
2. Potting Media
Being epiphytes, Cymbidiums require a free draining potting media that remains moist but not wet and also allows for air movement around the root system. The media should also provide the right environment for healthy root development and provide anchorage as the plant grows.
At Royale Orchids we have, through trial and error, created a Cymbidium media which we believe is second to none. It contains a blend of first grade pine bark*, coconut chips and polystyrene and is available at the nursery. There are also many good commercial mixes on the market and also some very bad ones. If inexperienced in the selection of orchid media ask orchid growing friends or orchid nurseries for their advice.
We use and recommend Van Schaik's Bio-Gro Bark Products from South Australia.
Contact Graham Crowder (Admin.Manager) 08 87231055 for further details
Repotting of Cymbidiums should be done once flowering is over and before hot weather sets in. Remove the plant from its pot and carefully remove as much of the old media and dead soggy roots as possible. If the plant needs to be divided do it now, making divisions of at least 3 green (leafed) bulbs and a lead, removing any excess backbulbs during the process.
As a general rule all orchids hate being overpotted, so when selecting your pot choose one that comfortably fits the root system and allows for 2 years of vegetative growth of the plant. Make sure that it has adequate drainage holes and that they are clear of excess plastic.
When placing the plant in the pot try to place the new growth/s towards the centre of the pot and the older bulbs towards the outer edge, this will give room for the new bulbs to develop uninhibited. Once in place start to fill the pot with the media, small amounts at a time, working it between the roots by tapping the side of the pot and some careful poking using your fingers. When complete the plant should be stable, with the bulbs buried to about 1/8 of their size.
The plants should be kept just moist and never be allowed to dry out completely, nor should they remain wet and soggy, especially during cold weather.
The following are guidelines only and will need to be adjusted to suit your individual conditions, some variables which will affect the frequency of watering include potting media used, climatic conditions, pot size/type, housing etc.
In general watering can be carried out every day or so during warmer weather and reduced to once every 10 days or so during cooler weather. But check your plants individually to determine if they need water or not.
There are many ways to fertilize your plants, the two most common methods are
Slow release granules (6-9 Month) - added around the top of the pot when repotting or at the end of flowering.
Liquid fertilizers - Half strength on a weekly basis
Or you may combine the 2 methods, supplementing the slow release granules with liquid feeding during periods of heavy growth.
Being weary that an over supply of nitrogen from December to March will inhibit flowering.
Keep this old adage in mind when fertilizing 'Weakly, Weekly'.
Cymbidiums are hardy plants and can withstand wide temperature variations from 1°C to 40°C. During extreme cold weather keep plants dryer. During hot weather keep plants moist and mist beneath the benches to aid cooling.
Odontoglossum Alliance Culture
Generally Odontoglossums do not require strong light to grow and flower. If on a bright day you are able to cast a faint shadow on the plants when waving your hand above them then you are supplying them with sufficient light, this kind of subdued light all day is preferred over stronger light for a shorter period. Naturally more shade will be required during summer
A sure sign of excess light is if your plants have a reddish bronze colouration on the leaves. Most plants with Oncidium in their makeup, such as Wilsonara's and Odontocidiums will be capable of tolerating higher light levels than most Odontoglossums, Odontioda and Vuylstekeara's.
2. Potting Media
Odontoglossums must remain moist at all times, so it is paramount that the media has good water holding capacity. Many potting medium have been used successfully throughout the years, such as bark mixes, peat mixes and rockwool. We at Royale Orchids have been using a mix of quality long strand Tasmanian Sphagnum moss and granulated polystyrene (70/30) with very good success.
Frequent potting is recommended for Odontoglossums, they complete their growth cycle in 9 months and are continually growing, so potting can be done at any time of the year. The fine root system is produced from the lead growth and emerges when the lead is about 100-150mm long. This is the stage at which the plants should be potted. Take the plant out of its existing pot and remove any old media and soft dead roots, pick an appropriate size pot to hold the root system, do not overpot. Moisten your Sphagnum mix and carefully wrap the existing root system in it then place it in the pot with the lead towards the centre. Use more mix to fill in the spaces, do not apply heavy pressure, just enough to keep the plant firm in its pot. You should be able to pick the plant up by the leaves without it falling out.
Odontoglossums come from the constantly moist cloud forests of the America's, and as such need to be kept constantly moist, being moist and being wet are two different things and should not be confused. When checking if a plant needs watering feel the mix -is it dry, pick it up - is it heavy / light.
An old adage, this one applies to watering - 'If in doubt leave it out'.
There are no hard and fast rules when it comes to watering, you will need to adjust your watering regime to suit your individual conditions, some variables which will affect the frequency of watering include potting media used, climatic conditions, pot size/type, housing etc.
Water in the morning to allow the plants to dry before night. This will help reduce the risk of fungal diseases attacking your plants.
Odontoglossums are not gross feeders. Large amounts of fertilizer will harm the plants and cause loss of the root system. It may also cause the sphagnum moss to go 'slimy'. The most often used fertilizing regime is liquid feeding at half or quarter strength. Again the weakly weekly adage is used here. Flushing the pots out occasionally with plain tap water will help wash out any excess salt build up in the media.
The optimum temperature range for Odontoglossums is a minimum of 8°C to a maximum of 26°C, but they will survive in lower temperatures provided they are kept on the dry side. They can withstand temperatures up to 40°C providing they are kept moist and the temperature does not remain high for long periods. Plants that contain Oncidium in their breeding will generally withstand higher temperatures without stress.
Pleurothallid Alliance Culture
Pleurothallids including Masdevallias, Draculas, Restrepias etc grow very well with Odontoglossums under the same general conditions. Refer to the Odontoglossums cultural notes for general cultural advice.
Repotting of Pleurothallids should be done during Autumn, after the Summer heat has abated, and the plants are about to resume their growth cycle but before the new root system has been produced. The same sphagnum moss polystyrene mix as used for the Odontoglossums is perfect for these plants. Dividing of plants can be done at this time also, making sure not break up the plants into divisions smaller than six or more leaves, potting into as small a pot as possible.
Pleurothallids will thrive under the same temperatures as Odontoglossums providing the maximum temperature does not exceed 30°C for prolonged periods. Under high temperatures keep plants moist, mist under benches and provide as much cooling as possible as these plants can suffer from stress or die in adverse conditions, especially heat.
A quite high light intensity is required to flower Cattleya's well. Grow Cattleya's in filtered light (30%-50% shade). If the leaves turn yellow, apply more shade. Be sure to avoid direct sunlight which will cause burning to the leaves. If grown in too much shade, growths will become soft and elongated and flowering will suffer.
2. Potting Media
Cattleya's have been grown with success in various potting medium including sphagnum moss, pine bark and other mixes. At Royale Orchids we grow our Cattleya's in our Cymbidium mix which contains pine bark, coconut chips and polystyrene. This mix holds moisture but does not remain wet. It also allows for good air circulation around the roots which is important as these plants are epiphytes in nature.
Potting of Cattleya's is done during Spring as the days warm up and root growth commences. This is usually when the new growths are about 100-150mm long. Remove the plant from its existing pot, clean away any old media and soft dead roots. Choose a shallow pot which will just accommodate the root mass. Place the plant in the pot with the new growth towards the centre and backfill with potting mix. Firm in and stake any loose growths.
Cattleya's have periods of growth and dormancy. This is indicated via the green root tips of actively growing plants. Plants in dormancy have sealed over root tips.
Keep plants constantly moist but not wet when in active growth which is generally during the warmer part of the year. During cooler weather when growth has stopped/slowed, watering can be reduced greatly to about once every 2-3 weeks, depending on your conditions. In heated houses, watering will be required much more frequently.
When the plant starts active growth and the green root tips are about 1cm long, fertilizing can take place. Liquid fertilizer is the most common method used at about half strength with every watering. Drench with plain water occasionally to flush out any excess salt build up in the mix. Fertilizing should taper off as the cool weather approaches and root growth slows. Do not apply fertilizers when roots are dormant as it may burn them.
Most members of the Cattleya alliance require minimum night temperatures of between 8-10°C for optimum growth but can drop down to as low as 1°C as long as the plants are kept in a dry state and the low temperatures are not sustained. Plants which contain Sophronitis in their breeding are more cool growing and do not need to be kept as warm.
Paphiopedilums grow well when they receive approximately 70% shade. This gives them good colour in their leaves.
If on a bright day you are able to cast a faint shadow on the plants when waving your hand above them then you are supplying them with sufficient light. This kind of subdued light all day is preferred over strong light for a shorter period. Naturally more shade will be required during Summer and less in Winter.
2. Potting Media
In cultivation the most common potting media used is pine bark. We at Royale Orchids have had good results utilizing our Cymbidium mix which contains pine bark, coconut chips and polystyrene granules.
For best results, potting should be done on an annual basis (At Royale Orchids we repot our plants in October/November when root growth is just commencing). Remove the plant from its pot, and shake out the old mix and remove any soft dead roots. Select a pot just large enough to contain the root system. (We have had good results utilizing Port Pots Long 80mm). Place the plant in the centre of the pot and backfill with potting mix, working it into the root system. Ensure that the plants are securely potted, utilizing stakes if necessary.
As Paphiopedilums do not have pseudobulbs or other water storage capabilities, they require watering throughout the year. During warmer weather, twice a week should be sufficient. In Winter, water every 7-10 days depending on the weather. These guidelines will vary depending on the media used, the size of the pot, your location, etc. Remember more plants are lost through over-watering than any other cause.
Paphiopedilums are not gross feeders and a similar feeding regime to that of Odontoglossums can be used.
In general plants with plain green leaves do not require as much heat as those with mottled leaves. All grow well in conditions between 8°C and 30°C.
Although Zygopetalums appear quite fragile, they are in fact very hardy and thrive under Cymbidium conditions. Please refer to Cymbidium cultural notes for their requirements.
Most importantly do not have these plants wet at night.
Australian Native Dendrobium Culture
These very hardy, rewarding plants are not difficult to maintain in cultivation. They require conditions similar to those of Cymbidiums except for slightly more shade and less fertilizer. See Cymbidium cultural notes.