ONCIDIUM SEASONAL CULTURE
Oncidiums are not the most popular of orchids today. It was, however,
the discovery of Oncidium kramerianum that brought the fashion of orchid growing to Great Britain in the
Victorian era, and which eventually extended to this country. With the current fashion of masdevallias or the Aussie
dendrobiums, for example, oncidiums have unfortunately been largely forgotten. They are, however, one of the
most easily grown and spectacular of all orchid genera, containing a wide diversity of plants that are often
the eye catchers when displayed at orchid shows. There are some hybrids being developed by connoisseurs, but even
the species make attractive and desirable additions to any orchid collection. Who can avoid admiring a multi spike
plant of Oncidium papilio or the long arching brightly coloured multi flowered display of Oncidium varicosum
var. rogersii. Oncidiums are a diverse genus, ranging from the large spectacular flowers of Oncidium
macranthum down to the diminutive equitants.
The genus oncidium is a relatively large one, with some 400 to 750 listed by various authors. Their
nomenclature - naming - is still under discussion, as some species have been moved around various genera by a number
of authorities. Whatever the final placement is, for growers it is the diversity and attractiveness of the flowers
that is important.
Available from some specialist orchid nurseries many can be seen and obtained
from orchid society shows run throughout the country. Amongst the uninitiated, orchids are commonly thought to
be delicate plants requiring expensive and extensive growing facilities. Oncidiums include amongst their numbers
plants which are strong robust plants capable of surviving quite difficult conditions, although of course, their
growth and flowering will be much better and more assured when their relatively simple basic requirements are provided.
There are, however, some oncidiums which are more delicate and which require additional care, but there are plants
attractive to all covering a wide span of skills and conditions. Most oncidiums require a glasshouse or protected
growing area, although the facilities provided do not necessarily have to be expensive or extensive. There are
some species and hybrids that can even be grown successfully with cymbidiums. There are many which can be grown
successfully in the home, in the bathroom, lounge or kitchen, on the refrigerator or TV or other suitable shelf
Oncidiums will be grown successfully in all parts of the country, although in the colder environments
additional warmth and protection will be required, especially for the warmer growing varieties. In a general guide
such as this growing information relevant to all areas cannot be discussed. What will be attempted is to detail
the general growing criteria, and the reasons for the various recommendations. This should enable any individual
to ascertain the general growing requirements and seasonal requirements. It is, however, recommended that anyone
new to growing orchids or in particular oncidiums, or someone moving to a new area, contact a local grower to ascertain
specific growing advice. In particular the members of the local orchid society will be only to happy to assist.
Joining a society is the ideal way to make new friends and to obtain the most assistance, but speaking to growers
at the society orchid shows, or even just obtaining the name of a local grower who may be able to assist over the
phone may be all that you require. Orchid growers are renowned for their enthusiasm for speaking about their favourite
plants, so never be afraid to seek assistance.
Most of the oncidiums grown have been come from plants native of Central and northern South America, from
a very diverse range of natural habitats - mountains, lowland forests, and even to semi arid deserts. For
this reason there are plants which can be grown that are suitable for almost all growing areas, skills and environments.
There is a range of both cool and warm growing plants to select from.
Most of the plants grow naturally as epiphytes, i.e. they grow on the branches of trees,
but, unlike parasites, they do not obtain nourishment directly from their host. A few grow on the ground as terrestrials,
in a thick mat of humus moss and leaf detritus, or in some cases even in swamps. There are also a few that are
lithophytes, plants which grow on rocks. Of importance to their culture is the fact that their roots are exposed
to the atmosphere; they require plenty of moisture, but their growing environment must not retain excessive water.
For this reason the use of normal garden soil will be disastrous, and the use of specialised bark growing media
and slab culture is required
Plants can be purchased in flower, and this is generally preferable for new growers. Small plants
can take 4 to 5 years from seed to reach flowering size. You can grow from seed yourself, but contrary to the usual
garden plants, orchid seed must be sown and germinated in sterile containers which new growers can find difficult.
Also, the establishment of plants from the flasks, while an interesting challenge, can be difficult for those without
experience of orchid growing, or lacking more than basic growing facilities.
Seedlings can be purchased, which will produce variable flowers even where the
same parents are involved, reflecting the variation and quality of the parents. A group of seedlings can be interesting
to grow, as you never really know what you are purchasing, and the variation in individual plants gives an added
interest. Many oncidiums will, however, be obtained as mericlones. These are laboratory produced copies of the
original plant. These allow selected and perhaps award winning seedlings to be propagated in large numbers for
wider enjoyment. If you see the original plant of the mericlone you will know that all its mericlones will be the
same. Mericlones have been a major factor in the improvement in plant quality, as the process allows the very best
of all plants to be made available at reasonable cost. Many plants will, however, also be obtained as divisions
taken from existing plants. In some cases old leafless back bulbs can be coaxed into growth, although not all can
be propagated in this way.
To understand the genus, it has been divided into sections, groups of plants which show affinity
to each other. The plants in any one section generally require the same or similar cultural conditions, and therefore
when considering their culture, this division has practical advantages, especially when there is a wide range of
cultural differences within the genus.. There are a number of books available that show the Sections the common
species belong to. If this information is not readily available, the fact that there are plants requiring different
culture is useful, as careful observation of growth etc. will help indicate what is best. If a plant is not thriving,
then you can make changes in the knowledge of general requirements.. If you are experiencing difficulty with a
particular plant it is worth finding out to what section of the genus the specimen belongs, and once you know this,
the following information will assist. Commonly grown species will be also noted in the relevant sections.
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ONCIDIUM SECTIONAL CULTURAL GROUPINGS
|GROUP 1 DRY ALL YEAR
This group includes
the Oncidium Section - the equitants or variegata, small compact plants
producing comparatively large brightly coloured flowers. Species include urophyllum, pulchellum, triquetrum,
henekenii and guiaense
The Cebolletae Section, with their rounded leaves include nudum,
cebilleta, stipitatum, jonesianum, cebolleta, teres and stacyi.
and the Plurituberculata (Miltoniastrum) or ‘Mule eared’ oncidiums
, this group characterised by their heavy flat leathery leaves. Species include altissimum, aurisasinorum,
bicallosum, cathagenense, cavesnishianum, haematochilum, lanceanum, lindenii, pumilum, splendidum.
The ‘dry’ requirement must not be taken literally. What is meant is that these plants come from habitats subjected
to drought and semi desert conditions, with the Pulvinata plants being specially adapted to survive the greater
degrees of dryness. After watering the plants must be allowed to dry out. The sections are listed in their increasing
ability to survive dry conditions. The group includes some 15% of all oncidium species.
GROUP 2 MOIST ALL YEAR
Over half of oncidiums are included in this group. The plant are in growth all year, and accordingly
must be watered all year, although this may be reduced when growth slows during the winter. This group can be further
divided in accordance with their temperature requirements.
GROUP 2 A MOIST ALL YEAR, COOL GROWING 7-10OC.
This group contains some 20% of all oncidium species. The main sections are -
Cyrtochilum Section with some 50 individual
species, is the largest section of the genus. Large spectacular flowers are produced including macranthum, falcipetalum,
lamelligerum, serratum aemulim, annulare, cordatum, detortum, falcipetalum, fallens, halteratum, incarum,
lamelligerum, ucescens, ludens, marranthum, orgyale, serratum, superpiens, amongst others.
Cimicifera Section with small inconspicuous
flowers Species include cimiciferum, exasperatum, ieirax, rotundatum, turpe
Serpentia Section characterised by their long
wiry twining inflorescence containing serpens and glanduliferum.
Rostrata Section, which are generally free
growing and flowering plants, containing cheirophorum, ornithorhynchum, angustisepalum, examinans, hartwegii,
Paucituberculata Section with minute
flowers the main species being aberrans, amoenum,raniferum, hookeri
Cucullata Section with species
with colourful and attractive flowers, including the species phalaenopsis, nubigenum and warscewtzeii
GROUP 2 B MOIST ALL YEAR, INTERMEDIATE GROWING 12-15 OC.
A number of plants requiring moisture all year, but which come from lower altitudes and requiring some
Glanduligera Section, with distinctive and
spectacular ‘butterfly; type flowers, the principal species being papilio and kramerianum.
Stellata Section, with neat and pleasing flowers,
oliganthum, hastatum and clowesii maculatum being typical.
Barbata Section species typically produce short
racemes of flowers in great profusion from compact plants. Examples are barbatum, longipes, and micropogon
Oblongata Section are vigorous growers and free
flowering on long inflorescence, include isthmii, leucochilum oblongahtum, tigrinum,cabagrae oblongatum .
Planifolia Section are again free flowering,
including ansiferum, baueri, ensatum, incurvum, sphacelatum, wydleri.
|GROUP 3 SEASONAL DRY/MOIST ENVIRONMENT
Plants from this group are characteristically from the Organ Mountains region of coastal Brazil, and are
subject to significant seasonal variation. Winters are cool and bright, and the plants are dormant. With the onset
of spring rains, new growths are broken and warm temperatures are experienced. With summer sun, bright conditions
are present, although shade is provided by the frequent mists and fogs. These plants typically require a long root
run, which can be best provided by mounting them on branches or logs of tree fern.
Pulvinata Section are compact growers, producing
long lasting flowers, and include harrisonianum, pulvinatum and robustissimum
Waluewa Section species are compact growers, and
also like a long root run, include lietzii and pubes.
Rhinocerotes Section, including longicornu and
Concoloria Section are moderately sized plants
which produce medium to large flowers, includes concolor, dastyle and hyphaematicum
Crispa Section species produce large flowers and
a magnificent display when grown well. Important species are crispum, marshallianum, gardneri, forbesii, enderianum,
sarcodes, and there are a number of attractive hybrids.
Synsepala (Varicosa) Section has long lasting
colourful flowers, and includes the species varicosum, flexuosum,
Verrucituberculata produce pretty medium
sized flowers not commonly seen in this country.
|GROUP 4 VARIABLE REQUIREMENTS.
In addition to the above reasonably distinct groups there are a number of sections within the oncidium
genus that contain have species which exhibit variable requirements. The Sections in this group include the Heterantha,
Planilabria, and the Excavata Sections . Plants from these sections are not commonly encountered in this country.
For these plants, you will have to observe their growth habits etc. and assess their likely requirements from the
above information. You may also have to resort to experimentation to ascertain their best conditions.
The general growing temperatures groups widely noted for orchids, and those required by
these oncidium groups noted above can be summarised as follows:-
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ONCIDIUM SEASONAL CULTURE
FOR MAIN GROUPS
All in degrees censius - SHOWN - (minimuim) desirable range
||'DRY' ALL YEAR
||'MOIST' ALL YEAR
18 - 25 (35)
(15) 18 - 20
12 - 16 (20)
(7) 8 - 10
18 - 25 (30)
(10) 12 - 15
18 - 25 (30)
(13) 15 - 18
20 - 30 (40)
(15) 18 - 20
14 - 18 (20)
( 8) 10 - 12
18 - 25 (30)
(10) 12 - 18
18 - 25 (30)
(12) 15 - 20
20 - 25 (30)
(12) 15 - 18
12 - 15 (20)
( 5) 7 - 10
18 - 22 (27)
( 8) 10 - 15
12 - 15 (20)
( 8) 10 - 12
18 - 20 (30)
(10 ) 12 - 15
12 - 15 (18
( 5) 7 - 10
18 - 22 (25
( 8) 10 - 12
10 - 15 (20)
( 5) 7 - 10
Enter a number in either field, then click outside the
Click Reset button to clear
Temperature O F: OC:
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Optimum range targets
All in degrees Celsius
Before anyone commences growing any plants, it is important to remember that successful growing requires -
* suitable temperature levels
* an adequate supply of water
* plenty of fresh moving air
* suitable light levels
* and a suitable level of essential plant food
If you are experiencing growing difficulties it is well worth remembering the above requirements and looking
at your culture on this basis. The specific cultural recommendations will be written with the above in mind, and
should provide the answers to the main requirements. Observation of your plants and their growing conditions is
always the precursor to success.
Remember that it is not what you do well that controls your growing success. Rather it is that which you
do worst. If, for example, you do everything else right, but forget to water the plants correctly, then the plants
will only grow to the extent allowed by the limited water supplied. If you then correctly water the plant, growth
will then be limited by the next factor not supplied to the optimum level required.
The entries will consider the general cultural requirements first, then specific seasonal recommendations
applicable to the listed plant groupings will follow.
- This is the time of the year that you will be enjoying the fruits of your years growing, plenty of flowers.
Oncidiums flower for much of the year, but with some seasonal peaks. If you select a number of plants carefully,
you can have flowers for most of the year. If you are missing a great display now or through the year, now is the
time to review your culture over the past 12 months, and, if necessary, to seek advice.
- The natural starting point is the time of commencement of new spring growth, especially the start
of new root growth. With some species (from the Crispa Section, for example) the onset of growth is spectacular
after winter dormancy; with others it is not so immediately noticeable. For those plants grown on slabs, it will
be more readily apparent, but for pot cultivated plants it will not be so obvious. If you observe the plants, the
signs of new activity can be seen. Growth will commence earlier in the north than the south, so you will need to
observe your plants.
- The flowers for most of the plants will be enjoyed on the plants, as many are not suitable cut
flowers. However, as many of the plants are compact and attractive in themselves, they still make attractive displays
- With the removal of the flowers and new growth commencing, now is the time for repotting
- Repotting, the replacement
of the growing material, is required when -
- - the plant has grown too large for the existing container or
- - the existing potting material has broken down and must be replaced.
- Most plants require repotting every second or third year as the material gradually breaks down
thought normal bacterial and fungal decomposition. Small plants will respond with increased growth with more frequent
repotting - say every six to nine months if some supplementary heat can be provided, otherwise every year. .
- Many other garden plants can be potted on i.e. placed in a larger container when they have outgrown
their existing one, with new potting mix added to fill the new larger container. With orchids this ‘potting on’
is not generally recommended. It is preferable to replace all the potting mix to give it a fresh start.
- Oncidiums are repotted in a variety of growing mixtures, which are generally bark based. It is
also beneficial to mount plants on branches or slabs of tree fern. A good potting mix must be free draining but
at the same time retain moisture. For most of New Zealand bark based mixes will be the best, most readily available
and least expensive. The watering habits of the grower can also influence mix selection. If you are compulsive
with the watering hose, then you will require a more open free draining mix. On the other hand, someone who neglects
watering, or is away from home for periods, may prefer a finer mix, one able to retain water longer. The size of
the container is also relevant, smaller pots tend to dry out quicker that larger ones. When selecting a suitable
potting mix consider the conditions over the whole of the year, not just a particular season. If summers are hot
and dry, you may think a moisture retentive peat mix may be best, but if the winters are really cold, the wet mix
under cold conditions will often lead to root death and in such situations you may be better to utilise an open
mix but have to water more frequently during the summer. This is a typical example of fine tuning requirements
to a particular locality.
- Commercial mixes are available, although you can make your own if you know what
you are doing. Commercial mixes also usually have fertilisers added which will last 6 to 9 months, and so can be
- Plants must be firm in the mix, but not too tight. You should be able to lift the plant in the
pot by its foliage and not cause it to fall out of the container 9 times out of 10. If most do, place the potting
mix more firmly; if none do, do not place the mix so tightly.
- If the division lacks roots you may have to stake the plant in the container. If it flops around
the new developing roots can be easily destroyed, so you need to be able to stop this occurring. Place the stake
near the rhizome, preferably as repotting is being done so you can see where the roots lie and ensure they are
not damaged. Often a tie around the base of the leaves to a short stake is all that will be necessary to secure
the plant satisfactorily. If you have to stake an already established plant, avoid the outside of the container,
as many roots circle the inside of the container. Placing labels against the inside of the pot can also damage
- After repotting is completed, keep the plant in a warm shaded position and keep
on the dry side for 2 to 3 weeks. It is desirable to mist the plants to avoid unnecessary stress but you need to
stimulate new root development as quickly as possible. The aim is to get as strong and vigorous growth as possible
which reaches maturity as quickly as possible to ensure maximum flowering the following year.
- As an alternative to growing in pots, many cons respond well to be mounted on slabs. Not only does
this add interesting variation to a collection, but many oncidiums respond vigorously to this form of growing.
- Suitable mounts are pieces of cork bark or cork branches, thin slabs of tree
fern, suitable pieces of driftwood or tree branches - especially citrus and manuka. Slab mounting is especially
suitable where higher levels of humidity can be maintained.
- I have also seen some oncidiums growing without mounting, just hanging in the air held up by a piece of
wire, but that is not generally recommended!!
- A number of ways of mounting plants are available -
- 1 A cut can be made in the mount, the plant carefully wedged into this.
- 2 Usually the plant is tied on by
- a thin monofiliament fishing line or
- b thin copper or plastic covered wire, or
- c. a piece of nylon stocking
- 3 Some plants can be glued directly onto the mount with a non toxic adhesive.
- A pad of sphagnum moss over and under the roots can aid establishment, providing local moisture
and humidity, although this can be removed once the plants are established on the mount.
- Slab mounted plants will generally appreciate a higher level of humdity during the warmer summer
season, but also generally all year if this can be provided.
- When mounting, consider the growth habit of the plant. Some have a long root run, so mount at the
top so there is plenty of room for the roots to grow. Others have a climbing scandent rhizome, and such plants
should be mounted lower down on the mount to allow this growth to occur. Remember to ensure the plant is firm on
the mount. If it is loose, any movement that occurs can damage or even destroy the developing roots, which can
set the recovery and re-establishment back several months.
- Repotting is usually only done in the spring, ideally just as the new root growth
commences, before the new roots are too long and which may be damaged during the repotting process. You can complete
in early autumn after the main growth period has finished, but the plants then do not have the same time to re-establish
before the winter. Only repot at other times of the year in emergencies.
- When you purchase new plants, it is often desirable to repot them into a new fresh mix or remount
them as this makes for easier watering. plants in a variety of growing media can make watering difficult as different
mixes dry out at different rates. Repotting also gives you the opportunity to check out the health of the plant
generally, but especially the root system.
- During repotting you may divide the plant if it has grown into a large multi growth specimen. Remember,
however, that a large specimen can be spectacular.
- When you divide a plant, remember that a flowering plant comprises 3 to 4 mature pseudobulbs. Smaller
divisions take several years to recommence flowering.
- Old leafless back bulbs are often removed from the plants during repotting and when dividing a
plant. In some cases these can be coaxed back into growth when repotted in a small pot on their own. They can also
be placed in a closed plastic bag containing damp sphagnum moss and kept in a warm shaded positon. A number will
break into growth again in some months, and once they have developed roots some 25 mm long they can then be removed
from the bag and potted up in the normal way. Only experience will tell you which species and hybrids can be propagated
in this way, but 'nothing ventured, nothing won'.
- Remember to re-label all plants, and divisions. A plant without a label and name looses much of
its value. While a species plant can be re-identified, with thousands of man made hybrids their identification
is usually impossible. The plant label should include the date of repotting.. Labels can be marked with a good
permanent marker pen, although a HB pencil will often be the most long lasting. Remember to check the labels periodically
as they can fade over time. In addition to the visible label, it can be beneficial to include another buried in
the potting mix as insurance in case the other is moved or lost.
- Always try to have plants with strong healthy root systems, as these will perform the best. When
purchasing plants one of the main criteria is that they have strong healthy roots, such plants will re-establish
in their new homes so much quicker and earlier.
- With warmer conditions gradually becoming the norm during the spring, pay increasing attention to watering.
Allow the top of the mix to dry out somewhat before watering. When you do water, apply plenty, ensuring there is
a free row out of the drainage holes at the bottom of the container. Water the plants once, then do it again a
few minutes later. Bark mixes in particular can be difficult to wet once they become dry and a double application
ensures they hold maximum moisture. 0ver watering is watering too frequently, not a reference to the amount applied
at anyone time. How often watering is required depends on the conditions where the plant is growing, the temperature,
and the nature of the potting mix - coarser mixes dry out faster then finer ones. In early spring, for large plants,
once every 10 days or so may be frequent enough. Smaller plants, and under warmer conditions, more frequent applications
will of course be required. Plants on slabs often require more frequent watering.
- As the sun becomes stronger towards the summer, increased shading may be required - the use of
30 % shade will generally be suitable, although those from semi arid habitats, the ‘dry’ group, will like stronger
light. Brighter light can lead to increased flowering, although such conditions can lead to unsightly burning of
the foliage. If you grow under bright light, increased ventilation and air movement is desirable, and if humidity
can be increased problems should be minimised. The use of a fan running alal day and night can be of significant
assistance in reducing burning. Leaves should be of good texture, and of a light yellow green colour; dark green
foliate generally indicates too little light is being provided.
- Plants growing strongly will benefit from the application of fertilisers. When bark mixes are utilised,
a high nitrogen fertiliser is generally considered appropriate. Once growths have matured, reduce the nitrogen
component, and increase potash. Wither use liquid or dry fertilisers, applied at the rate of around half the manufactures
general garden recommendations. A little fertiliser often is often the best.
- Group 1 plants require very good air movement. Any repotting should be in coarse bark, or on fern mounts.
After flowering, the equitants require up to one weeks rest, the other sections require a dry rest of two to three
weeks. They also need a 20 degree Celsius diurnal (day/night) temperature variation to flower successful. Nit to
light shading, is appropriate, and a 3 to 5 day watering cycle is indicated, which can be shortened under hot conditions
- Group 2 plants also require good air movement. Medium sized bark is required for repotting, although
some of the cooler growing fine rooted plants can take a midium/fine mix. Free drainage is very important. The
cool growing species do not require a rest after flowering, although the intermediate temperature requiring plants
will appreciate a short resting period.
- Group 2 A plants, the cool growing ones, should have medium shade levels maintained. These plants must
be kept moist all the time for success.
- Group 2 B plants take medium shade at this time of the year, and can take a short dry period, say a
1 to 2 day wet/dry cycle, but should never be allowed to get completely dry.
- Group 3 plants naturally experience seasonal variation, and require a medium to coarse potting mix,
or mount on suitable material. They require a long root run, which must be provided for success. The appreciate
a 1 to 2 week rest period after flowering is completed. A moderate 10-15 oC diurnal temperature range is desirable.
These plants need little shade at this time of the ;year, and should be watered heavily and humidity kept high
as soon as new growths appear in the spring.
- The growing season will now be well under way. Root action will be strong and the new growths should
be developing strongly.
- With temperatures now increasing towards their maximum, the plants should be in their summer homes.
As most oncidiums will be grown in a glasshouse all year, increased attention to shading, and to ventilation is
- Plants can be kept under 30% shade generally, although some sections as noted respond to more sun.
- Do not crowd the plants too much as plenty of fresh moving air is essential. The use of fans will
- Increased watering will be necessary. As this is the main growing period, do not stint this work
as you do not want to give the plants any check to their active growth. If you are going away on holiday try and
get someone to water the plants, but make sure they understand what is required, as if they are not used to orchids
they could cause damage, even loss of plants. In a glasshouse, the use of misting sprays over and under the benches
can be beneficial by increasing the humidity levels.
- Most oncidiums are relatively pest and disease free. If a continuing problem does arise, look closely
at your culture as many problems can be solved without resorting to the use of chemicals. . If any pests or diseased
do become established, approach your local garden center for specific advice on products and how they should be
most effectively applied. Check that the products are suitable for orchids, as some are sensitive to some products.
Always test on a few spare plants first for safety before applying to all the collection. Remember all sprays are
poisons and must be used with care.
- Around mid summer, reduce the application of nitrogen fertiliser and increase the application of
- Group 1 plants like light medium shading and a 2 to 4 day watering wet/dry cycle is desirable.
- Group 2 A plants find medium to heavy shading is appropriate. Plants must be kept moist, with watering
increased as summer temperatures increase.
- Group 2 B plants require medium shading.
- Group 3 plants require light shading and maintain watering and keep humidity as high as possible, misting
over and under the plants can be ideal.
- With the development of cooler autumn conditions, any summer shading can be gradually removed.
- As conditions cool, reduced watering will also be appropriate. Avoid overhead watering, especially
if cooler conditions are anticipated, as water lodging in the growths can lead to their rotting. Generally it is
desirable to always water early in the day to ensure the plants dry before nightfall, especially in the autumn.
- Continued fertiliser applications are appropriate, but adjust the amount of application to the
amount of growth taking place.
- With more flowers appearing, continue staking plants, using cane or wire stakes. If you are using
wire, turn the tops over and watch your eyes don't get poked out when working with the plants.
- Bring the plants into the home and enjoy the flowers.
- When moving plants, ensure they are returned to the same orientation to the light source. Turning a plant
can cause the flowers to become twisted, spoiling an otherwise attractive presentation.
- If you are growing without heat under cool conditions, tend to keep the plants drier than usual,
as wet cold conditions are often fatal to roots.
- Minimum temperature requirements for the various plant groups noted previously should be followed.
Mature plants can be grown cooler, but growth will be reduced. The growth of small plants will be facilitated if
temperatures some 5oC. higher than is indicated for adult plants is maintained, ensuring the period to flowering
is reduced to as short as possible. Ensuring minimum temperatures are met will result in overall better growth
and flowering. If heating is required, ensure all systems are 'go' before the winter, as you do not want to be
caught out when a sudden cold spell occurs. Remember that once supplementary heating comes on, the atmosphere can
dry out quite quickly, and careful extra misting of the plants may be required.
- Avoid giving the plants a check in their growth for any reason, as once this
occurs it can take quite some time for optimum growth to be re-established.
- If you are growing without heat under cooler conditions, tend to keep the plants drier than usual,
as wet and cold temperatures are fatal to roots.
- Small plants in particular appreciate some additional warmth, and the use of
bottom heat provided by a heat board or warming bed can be most beneficial and economical way of ensuring their
maximum growth to reaching flowering size as quickly as possible.
- As plants mature, adjust watering as appropriate, and increase the amount of light to the plants
- Group 1 plants, incrrease light levels to full sunlight, or just very light shade. Decrease watering
, giving a 3 to 6 day wet/dry cycle
- Group 2 cool growing plants, give medium shading, and keep plants moist but never wet.
- Group 2plants requiring intermediate conditions , increase light by giving light to medium shading
and maintain a 2 to 3 day wet/dry watering cycle.
- Group 3 plants requiring seasonal conditions will generally need little or no shade at this time of
the year. When plants mature reduct watering and humidity, and ower temperatures to mature pseudobulbs .
- Adjust the amount and frequency of watering to the conditions being experienced. Maintain watering
if it is warm and sunny. If cold dull days are prevelant, reduce the amount and frequency of watering as many plant
roots can be lost under cold wet conditions. If in doubt it is better to err on the dry side.
- Adjust the amount of fertiliser being applied to the amount of plant growth taking place. If a
particular plant is dormant then it is a waste of money to apply a lot of fertilsier. Where there is reduced growth,
apply, but at reduced rates and frequency.
- Spotting and insect damage can affect flowers. With lower evening temperatures,
humidity will increase, especially after a warm day. Good ventilation and air movement is essential.. The use of
fans, especially in a glasshouse, is beneficial. Water on flowers can cause spotting, and therefore overhead watering
at this time of the year is not recommended. Slugs and snails can also cause damage, and may need to be controlled.
- Now is the time to enjoy your growing success. Taking some time will ensure your growing efforts
are presented to their best.
- - ensure the pot is clean, with all dirt moss removed
- - remove any dead leaves and old leaf bases from the pseudobulbs
- - clean the foliage of any old spray residue, dirt, dust etc. Remember when wiping down the foliage, hold
the leaves by their bases and wipe from the base to the tip. The leaves, especially from the newer growths, can
be easily pulled off if care is not exercised.
- - ensure the plant is correctly labelled, especially if you are going to present it at a show.
- .The plant has expended considerable energy in producing the flowers. The best results will only
be obtained if the plants are healthy and in good condition. If there is any doubt regarding the vitality of the
plant, the flowers should be removed quickly. It is generally desirable that flowers be removed form the plants
2 to 3 weeks after opening.
- Group 1 plants require nil to light shading, and a 5 to 7 day watering cycle is indicated, which can
be extended under cold conditions without harm.
- Group 2 A plants, should have medium shade levels maintained.
- Group 2 B plants take light to medium shade.
- Group 3 plants take full sun. These plants require little watering at this time of the year, other
than a light misting on warm days to prevent undue shrivelling of the pseudobulbs.
Shade requirements can be summarised as follows in general terms.
NIL = full sun
MEDIUM = on a bright day, a hand placed between the sun and the plants casts a clear
but not bright shadow (30%? shade)
HEAVY = hand shows only a faint shadow (say 50%? shade)
ACTUAL REQUIREMENTS WILL VARY DEPENDING ON THE LEVEL OF LIGHT EXPERIENCED IN THE PARTICULAR
LOCALITY.. SEEK LOCAL ADVICE FROM A LOCAL GROWER OR LOCAL ORCHID SOCIETY FOR LOCALLY RECOMMENDED ADVICE