catasetums cultivation, in Malaysia

it has been almost two years since i started collecting catasetums orchid, from a beginner who know basically nothing about catasetums (not to mention i killed my first one) basically i had about 25 different types of catasetums hybrids and species in my collection to current day.

Catasetums are in the family Orchidaceae, subfamily epidendroideae and bla bla bla....(i am sure one can look out for these info from the internet)

The reason i posted this is to share the experience on catasetums cultivation here, in Malaysia or regions where the weather is hot and humid all the year round. Basically till current date i had not come across many post on catasetums cultivation in tropical climate.

POTTING MEDIA

many different media for potting i had tried before from sphagnum moss, coconut husk chip, charcoal, broken bricks, fern slate and pieces of small logs.

From my own experience, coconut husk chip or coconut husk provides excellent humidity level for the roots but high percentage of fungal infection and also mold contamination. i had tried soaking the coconut media in bleach solution overnight followed by overnight immersion in plain water, but after sometime of planting, molds tends to set in and retards the growth. Monthly spraying of antifungals tends to reduce the problems.

Sphagnum moss also are good potting media for catasetums but extreme attention to be paid to watering schedule as over watering can be a problem, especially for starters. i usually water them once the most is partially dried out. However, i tend to find eventually all the moss tends to support a lot of algae growth as well.

Fern slate and pure charcoal media had the least algae growth, fungal problems or even mold problems but they require twice a day watering regime. These media provides excellent aeration for the rooting system and i had the least problem with rotting with these media.

FERTILIZATION AND WATERING

Since i am using mostly 100% percent charcoal media with clay or plastic pots with fenestration on the side for better aeration. I tends to water my catasetums twice daily with quarter strength fertilizer (21:21:21). i dun switch to blooming fertilizer but intended to give it a try for mature plants in the future.

PEST AND DISEASES

The most common pest problem for catasetums are red spider mites (tetranychus spp.). they tends to hide under the foliage and can really kill off baby catasetums. Mature plants are more tolerant but they causes discoloration and spots on the foliage, especially on the ventral side of the leaves. though frequent spray with pesticide can solve the problems, but for flowering plants this might be a problem because there are several occasions where the flower buds drops in the mid way of formation once come in contact with the pesticide.

Fungal and Fusobacterium can cause nasty rotting problems on catasetums but once a month watering with antifungals tends to reduce my problem with fungal. sometimes i used 1:10 dilution of bleach as disinfectant for both but remember to flush the plant thoroughly with water 10 minutes after application (learnt about this method in orchid forum from a senior member and thank you very much for that Betty). however i dun recommend this method for baby catasetums for i found out that they dun tolerate it as well as mature plants. (perhaps a lower dilution is needed but personally i haven't tried this out yet)

all my plants are place under a black plastic shade, 24/7 outside in my garden. due to the weather in our country where it rains basically throughout the year i had adopted the daily 1/4 strength fertilizer watering system to reduce the effect of bleaching by the rain.

PROPAGATION

catasetums are easily propagated by dividing pseudobulbs. some people recon the division into two pseudobulbs per division, some one bulbs per division. in addition to that, some would recommend the division during a new lead is form and while others does the division during the dormant phase.

so far i had been doing both but i still divide them during the dormant phase most of the time. in addition to that i usually divide the bulbs into single bulb and i trimmed off all the old roots. after each division i would treat the cut surface with some antifungal powder. some catasetums grower would leave some of the old roots behind to act as support during subsequent re potting but personally i dun practice this method.

another method of propagation is by seed flasking! i started my first catasetum pollination recently (27/5/2011) and in order to do this, you need to have catasetums that flower both female and male flowers on the same time (for those who are not aware, catasetums flowers are not perfect ie male and female are in separate flowers but there are chances where you can get a hermaphrodite flower.

for those who started with catasetums, please take note that unlike some other orchids, catasetums had an active growing phase and a dormant phase. when a pseudobulbs fully matures, they either send out a new lead or go into dormant phase. the leaves will gradually whiter and they will remain there for several months. don't worry, they are not dying and i had come across several post where people were asking for advice where had they done wrong to the catasetum plant when the leaves are shedding.

during the dormant phase, keep watering to the minimum, depends on the environment it is potted but i sprinkled some water like once a week, just enough to avoid the bulbs from shriveling.

but i dun practice the once a week misting for divided bulbs, only for dormant plant.

WELL, THAT IS ALL I HAD TO SHARE FOR THE TIME, AND PLEASE TAKE NOTE THAT THESE ARE MY PERSONAL EXPERIENCE AND THE PURPOSE OF THIS POST IS TO PROVIDE SOME INITIAL GUIDE FOR THOSE WHO ARE INTERESTED TO GET STARTED WITH CATASETUMS ORCHIDS.

i personally also welcome any second opinion on other catasetums cultivation methods. \