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|Vol. 11(1), pp. 2-4||The McAllen International Orchid Society Journal||January 2010|
The idea of orchid "WANTS" was the subject (some time back) of a presentation of Mr. Weyman Bussey to an orchid society in I believe) Hawaii. The following article is a continuation of one begun in the last issue. In that issue the first four "wants" (water, air, nutrition and temperature) were addressed, and the article now continues (and concludes) with the fifth of the "wants."
Whether you grow indoors, outdoors, or in a greenhouse, you need to learn how to adjust the five basic factors influencing the growth of your plants. These factors are all interrelated and by altering any one of these factors, you will be required to adjust the other four. They must be balanced and the key to successful orchid growing is moderation in all aspects. The solution is relatively simple: visualize your personal wants and needs, and apply them to your orchids! If you lump Air, Temperature and Sunlight together, we can call them climate. What climate do you like? Face it, when you are comfortable in a climate, your orchids are comfortable. If you allow your plant's ambience to become so hot you can't stand it, most likely your orchids can't either! Remember their "WANTS": There's one for each finger on your hand:
Water - Quality, quantity and frequency.
Air - Quality and movement, for gas exchange.
Nutrition - Fertilizer, vitamins and alcohol.
Temperature - They do not use clothing!
Sunlight - The ENERGY that makes food.
Put each first letter together and you have WANTS. It's that simple. Now we'll break down each factor as far as time and space permits in this issue.
Light intensity, or the amount of sun light, is a simple factor, easy to express and understand. In the USA it is normally expressed in foot candles. In Mexico most of the orchids come from deciduous oak forest which lose their leaves for three to five months out of the year. During this time many species are exposed to full sunlight. At high elevations, we are talking a maximum of 10,000 to 12,000 foot candles of light at noon. Remember, they usually get broken shade from branches above or cloud cover, so the exposure is seldom continuous.
In terms of shade cloth, 50% to 63% shade will provide optimal conditions for the growth and flowering of most species and hybrids during the summers in South Florida. A lush green plant many times will not flower. If you have plants that are green and pretty, but never flower, try putting them in brighter sunlight. Avoid sunburn or scorching of the leaves. This may occur when you make the transition from too much shade to adequate sunlight, remember moderation. It initially appears as a lighter area on the leaf which gradually turns black from the center outwards. If the damage is done, cut off the leaf using a sterilized implement just below the burn. The new growth will reward you with flowers and hard sturdy pseudobulbs.
Since not all plants are adapted to strong light, below is the recommendation for genera and species according to their light requirements in the Mexican chart and also listed are the popularly cultivated genera of other orchids which you might already grow well in your collection.
Orchids are orchids and many come from similar habitats. If you have the knowledge base of other species and hybrids you build upon your existing knowledge. If you lack experience and want to learn, participate actively in your society, travel to shows and show your plants or just observe. You may have a preference for a particular group of orchids. Compare the groups by culture and try to be particular about the plants you are seeking for your collection. Of course, measurements are not precise: they can fluctuate 10 % up or down in many cases without harm. However, remember, the stronger light you provide the more you will have to provide of the other WANT factors, and you will be pushing the limit on optimum or even maximum growth.
Finally, for culture, we come to the DIM part of orchid growing, (= Disease, Insects and Media), where we choose what will anchor our plants and protect them from unwanted attacks. As important as the WANTS are the remedies for your plant illnesses. When it comes to disease, an ounce of prevention is worth a pound of cure! Disinfect tools. Periodically clean benches. Keep weeds out. Speaking of weeds, one should try using KARMEX, but make sure it has only Diuron as the active ingredient. Use 1 tablespoon per gallon and it will control all weeds, including Oxalis. Use a small hand spray bottle and try to cover the weed leaves well. It takes the weeds a few weeks to die, but they do, it won't hurt the orchids. Space your plants to provide good air circulation and light. Set up a preventative spray program alternating fungicides and--at times--combining them. One shotgun method for root problems is a combination of Subdue, 1 oz (9 drops/gal.), and Cleary's, 1/4 lb (1 tsp/gal) per 100 gallons. This is watered into the pot every 20-30 days and gives 99 per cent effective control of root diseases. If one has good air movement and does not over-water, disease should be no problem. Remember: if a disease shows up, first identify it, then find out where it comes from; what causes it; and what specific insecticide or fungicide will cure it or prevent it. Point: fungicides are specific to certain fungi and one brand will not control all of the different fungal diseases. A little investigation can save an orchid grower a lot of money and a lot of plants!
Spray for insects only when necessary, and only for the specific insect attacking the orchids. Many insects are beneficial, so one needs to be careful with insecticides and use them only according to the specifications on the label. Watch out for cockroaches, slugs, snails, rats, rabbits and squirrels, as they all may partake of the green leaves and roots made so readily available. Observe for bugs. Drop in on the orchids at varying times of night and quietly observe the activities going on in the collection. You may be surprised how much is seen. I have used about every insecticide during my career. The only insecticide this grower (Bussey) really recommends currently is Orthene. It seems to control everything and doesn't hurt the plants. Its recommended use is 2 tablespoons in a six gallon end of the hose sprayer; and wetting the plants as if one is watering.
The growth media and watering go hand in hand. The media can be many things; ground barks, volcanic rock, calcined clays, tree fern, Osmunda fern fiber, pieces of wood or cork slabs, even old shoes! The species will determine which media to be used, and by experimentation the orchid grower will discover the one best suited for the species and the greenhouse. In general, the "best" media to use is one that's available at a reasonable cost. Use what is available and experiment. All media should provide; support for the plant (that eliminates Styrofoam pellets!); aeration (roots breath too!); drainage (don't plug the holes in the pots!), and some buffering capacity (the ability to absorb excess salts). Most plants will do equally well in pots or on plaques if one pays attention to the increased need to water.
A previous article outlined certain "W" questions. Who & Why: You have to decide what plants you want to grow and why you want to grow them. You need to learn how to identify them, or else buy them with a label, so more information on their cultural requirements can be found to help supply their needs. If they are hybrids, one needs to understand the climates from which their species ancestors come, and how those species grow in their native habitats ("where"). In short, it eventually comes back to studying species, and if one is dealing with a hybrid, there will be questions about which ancestral species (one or more!) is/are the most significant in what the particular hybrid has for "wants" for its best culture.
However, still another question remains, and it has to do with "when." When any of this studying is going to be done is another "W" question that can only be answered by the grower! If one is going to grow orchids, and do it well, some studying is mandatory! One cannot just throw an orchid plant onto a window sill or hang it out under a tree and expect it to flower season after season unless that habitat is close to what it experiences in nature! Only a totally non-thinking individual would assume that any plant would do well with no care when lodged on a window sill or a back yard tree! The problem is that the world seems to have an abundance of such individuals! Orchid species hail from far too many habitats, and they are not for the non-studying individual!