LYCASTE ORCHIDS GENERAL CULTURE
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Heading photo Lycaste Concentratin

 

INTRODUCTION

LYCASTES comprise an interesting and striking group of orchids. The following are general culturenotes. The monthly cultural calendar

General aspects of culture are discussed below under relevant headings. Certain elements of theapplicable culture follow where the particular requirements of the relevant Sections of the genus will be discussed.


I MEDIA

The mixes applicable to cymbidiums are generally adequate although the sieving out of the fine material from barkmixes is often beneficial, in order to ensure fullest drainage. Those species which have the most marked growthcycles, the spiny pseudobulbed Deciduosae species, willrespond to a coarser mix which can dry out during the usual winter rest period. About 7 to 15 mm sized pieces ofbark for these are appropriate. Other section species generally require a more even supply of moisture to be availableto the roots, and the inclusion of finer material, down to say 5 mm sized pieces, with perhaps the addition ofsmall quantities of sphagnum moss is more appropriate. However, watch the sphagnum moss, as this material can breakdown quickly, making conditions unsatisfactory, especially if heavy fertiliser usage is followed.

All bark should be soaked before use, in water containing some fertiliser

Lycaste Auburn

2 POTS AND POTTING
For the Deciduosae, those species which dry during thewinter, and who have roots which in nature are exposed on bark surfaces, require an open mix in generally smallcontainers, i.e. tend to under pot. Other species such as macrophylla, skinneri

Clay or plastic containers can be chosen. I have had success with both, although I feel the best growth has beenwith clay containers, with the bottom drainage hole enlarged with crocking to the bottom third. Rigid plastic containers,with extra drainage holes are satisfactory.

The actual process of repotting follows usualpractice. Pot in the spring, ideally just as the new root growth commences so that re-establishment is as fastas possible, usually when the new growths are 100 to 150 mm long. Carefully remove the plant, and clean away theold mix and any dead roots. You can divide a plant now by breaking the rhizome, although often it is better tocut the rhizome where desired earlier before the growth is broken in the spring, so the growth on the back cutdivision can be got away before it is removed and separately potted.

Try and repot firmly but not too tightly; some staking may be required to hold the division if there are not manyroots left. Place the base of the pseudobulb some 10 to 15 mm below the top of the pot, with the mix just overthe rhizome. After repotting keep the plant warm and shaded and just damp until new root growth is apparent. Donot forget to relabel all divisions. Old back bulbs not growing can be removed, and placed in a small pot, or ina closed plastic bag with some sphagnum moss. Many will break into growth after some weeks, when they can be placedon a small pot once new roots start to form. All flowering divisions should contain at least three pseudobulbs.

3 TEMPERATURE / HUMIDITY

There are a number of species which come from low altitude habitats

These plants appreciate a humid atmosphere, which usually cannot be provided adequately when the plants are grownin a home. Free moving air is essential for their well-being; the use of fans running all the time is most beneficial.Aim to keep the leaves moving gently m the air current.

 

Lycaste deppei 'Putnam'

4 SHADING

Shading is very necessary during the spring, summer and autumn as burning of the thinplicate foliage can easily occur. The maintenance of a constant air flow and higher levels of humidity will preventburning in a lightly shaded glasshouse. I generally grow with light shade for most of the year, with medium shadeduring the summer period only, but with good air movement and humidity control. Stronger light will generally ensurethe strongest growths, and maximum flowering.

5 WATERING

The Deciduosae must receive warm humid conditions whenin growth, but during their winter dormancy, just lightly water or mist to prevent undue shriveling of the pseudo-bulbs.The Macrophyllae and Fimbriatae Section species should be kept moist all year, the actual frequency of wateringobviously changing with-varying seasonal conditions.

At all times do not overhead water The new growths comprise a 'tube' structure which can easily hold water. Ifthis occurs, and cool conditions arise, often rotting of the growth can occur.

Water freely when this is completed, allowing plenty to pass through the mix to wash away any salts which may haveaccumulated. Fowlie notes that generally Lycastes are high altitude plants which are very sensitive to salts containedin the water. If you are in doubt about the water supply, use rain water, although generally most piped supplieswill be found to be satisfactory in this country.

6 FERTILISERS

Some of the species grow in thick humus mats, and heavy fertilising of these plants will generally be appropriate.The Deciduosae Section species and hybrids also requiresome fertiliser, although the lower levels of application can be given. Always relate fertiliser usage to the growthrate of the plants involved The use of a balanced general fertiliser is satisfactory, although a higher nitrogenratio is important in the spring. A little fertiliser often is a good generalisation for new growers. If heavyfertiliser usage is considered, always ensure the growing mix is kept moist. In such situations if it is allowedto dry out, often damaging concentrations can accumulate in the remaining water in the mix, which can kill theroots. The use of capillary watering techniques can be useful in such situations to overcome this problem.

7 PESTS AND DISEASES

Generally lycastes are pest and disease free, although insecticides and fungicides may be necessary at times. Usein accordance with normal orchid growing practice. It is, however, appropriate to note that some products can damagethe thin plicate leaves, some of the systemic products in particular being damaging at times. Always check a newproduct on a few spare plants to test their reaction before applying to a whole collection.

8 GENERAL

Successful flowering is dependent on growing a large plump pseudobulb. Lycastes are clear in showing their appreciationof good culture. Where conditions are not fully appropriate, pseudobulb growth will be restricted, but where everythingis fully to their liking, large plump pseudobulbs. will be quickly produced.

Spotting of the thin plicate leaves often indicates overhead watering has been wrongly used, often associated witha lack of air movement. Severe spotting can also indicate root damage. If these signs appear, quickly considerthe main elements of your culture, and take the necessary corrective action your study indicates is appropriate.Most species loose their leaves over the winter, so any unsightly foliage can often be removed once the pseudobulbsare made up.

With the hybrids, the applicable culture will usually be the average for the species involved, weighted in termsof the proportion of each species in the hybrid. If this is unsuccessful, especially in a hybrid containing speciesfrom diverse habitats, experimentation will be necessary, with the conditions for each species tried until successis obtained. Once established, most are readily adaptable to glasshouse culture. With all culture, try and ensuremaximum root growth. If a strong healthy root system is maintained, generally the rest of the plant will prosper.

9 FLASK PLANTS

Many people have problems with the establishment of flask plants, and it is hoped the flowing notes may be of assistance.
Deflasking will generally be most successful when completed in the spring. Generally, deflasking should not becompleted until the plants have formed small pseudobulbs in the flask although if the leaves have reached the topof the flask then deflasking should be completed. Narrow necked flasks are broken after being wrapped in newspaper,by tapping with a hammer or crushing in a vice. Wide necked flasks allow plant removal without breaking of thecontainer. The traditional method is to remove the agar, and, perhaps wash in water containing a weak fungicide.While the plants will be sterile on removal, this may prevent any fungi becoming established in any wounds whichmay have occurred during the deflasking process.

Separate the plants, and dry on the paper. If community pot planting is to be followed, grade the plants to similarsizes for each pot. The individual plants can be potted into suitably moistened seedling grade bark, in individualpots or together in community pots. A successful alternative technique is to place in loosely packed sphagnum moss;this ensures moisture is available, but also provides plenty of air to the roots, which is most important. Thiscan be a most successful method.
Keep freshly potted plants warm and shaded. A plastic bottle or bag 'tent' can initially be useful to maintainadditional humidity. As plants establish more air can be given, and some weak fertiliser applied once growth isstrong. Kllen (D.M. Killen, 'Growing Lycaste Seedlings from Flasks', A.O.S. Bulletin) has suggested that deflaskedseedlings, because of their long thin roots which are invariably intertwined, should be planted initially as aclump, as removed from the flask. She recommends filling a 100 mm pot half full with large sized bark, with smallgrade bark then to 25 mm of the top of the container. The unseparated clump of plants is placed in the pot, withthe pot then filled with fine bark. The clump should not be buried too deep, the roots just covered, not the pseudobulbs.Grow in humid areas with good air circulation with fairly low light levels. Leave in the clump until the new growthsdeveloped on the first pseudobulbs are 25 to 50 mm high, then separate and repot the plants with bulb and growthinto small pots. The very smallest plants are placed in a standard community pot if appropriate. This recommendationseems worthy of serious consideration.

Small plants can be also grown in a mix of 50~o rough peat, with the fine material re-moved, with pumice and sharpsand added. This mix can contain a slow release fertiliser such as Osmocote. Pots with this mix can be placed ona capillary watering mat to keep moist, and the higher fertiliser levels often used do not cause damage becausethe pots can be kept near their optimum maximum moisture holding capacity. Every few weeks, flush the pots withplenty of fresh water to remove any possible salt build up.

THE LYCASTE SECTIONS WITH SPECIFIC CULTURAL INDICATORS

This discussion is based on material of the late J. Fowlie as he published in the great magazine The Orchid Digest,and his book The Genus Lycaste.

THE SECTION DECIDUOSAE

This group of Lycaste species is, with one exception, wholly from the North American continent. All the speciesof this Section, with the exception of tricolor are prominentlyarmed with spines on top of the pseudobulbs arising from where the leaves break off, and which live in the driersections of the regions where they are known to occur. They usually grow as epiphytes on trees or on rocks, inclose proximity to semi- permanent streams or rivers. A total of ten species are included by Fowlie in this groupcrinita, cruenta, campbellli, brevispatha are from the Pacificslope drainage system aromatica, deppei, and primarily from the Atlantic drainage area, but do range to the Pacificslopes. Macrobulbon is only found in the Caribbean catchment.Tricolor is strongest in the Atlantic Costa Rica region althougha small dwarf race has been found on the Pacific slopes. Lasioglossarepresents a relict form in Fowlie's view, linking this Section to the Macrophyllae