How To Grow Orchids
Forward:
This writing comes at great expense and hardship. On my part, only the time spent on writing and editing. But mostly the lives and souls of many good orchids who gave their all to survive in spite of me.

This writing is not dedicated to them, but the poor orchid souls who will die at the hands of the governments around the world, who could save or at least give them a chance by killing the plant portion of CITES instead of killing more plants.

Enough philosophy, lets get on with saving what we have or may soon purchase.
Assumptions:
This is written from the perspective of greenhouse growers, since I only have about one year of light gardening experience (1977). The majority of this paper should benefit all growers by giving them a place to start.

When I began in the art of growing orchids, I was fairly successful. But the occasional death of some plants later proved to be totally unnecessary. I had assumed that what the well known orchid growers who wrote the most acclaimed books of our time would tell me exactly how to grow all kinds of in central Alabama.

Well duh! Fortunately only a handful of plants died needlessly before I woke up! This writer knows you have a brain, but can only assume you will use it. The style of writing that follows is an attempt to start you in that direction and give you an edge by giving you some hard learned data gained from other growers and a few years of growing orchids.
Picking The Plants:
My greenhouse is a large structure (1000+ sq. Ft.) that is cooled by a 2 times per minute air exchange and a wall of Kool-Cels. I keep the minimum night temperature in winter at 60 degrees F. These conditions allow growing a wide variety of plants. The warm blooded Vandas, Phals, etc. Would enjoy 65 better but perform well.

The intermediate and a few cool growing plants would prefer 55 but they also do fine at the 60 degree mark. The night temps in summer are a different matter. These can go as high as 70-72, the Phals and Vandas eat it up but the Masdevallias and Odonts hate it. Beginners should avoid cool growing plants and stick to warm(60-65) and intermediate (55-59) growers. These numbers reflect minimum night temps.

Maximum temps in my greenhouse are set at 78F for the first exhaust fan to come on and 81F for the second fan and the Kool-Cel pump to start up. This setup has held an 82F maximum with an external temperature of 102F.

The point of all this is that if you have an 82F maximum and a 60F minimum you can grow almost any orchid. But if you don't have the cooling system, don't beat your head into a wall by buying Phrag. Bessiae at $150 a pop and wondering why it died. Stick to warm growing orchids like Vandas, Encyclias, Phals, etc.

Your use of good judgment in selecting orchids to match your growing conditions and micro-climates and self-control at orchid ranges will add to your sense of accomplishment.
Top of Page
Light:
This is very related to the prior topic in that if you don't have the light levels to grow Vandas, Schomburkias, etc., and don't intend to cut down trees around the greenhouse or put that new roof on the greenhouse, don't buy them and watch them turn dark green and never bloom.

While we are on the subject of leaf color lets talk. I was once told that I was not giving my Vandas and Ascocendas enough light due to their rich green color. Well I ignored the remark because they were getting 4000+ footcandles all day long with no trees shading the greenhouse.

Depending on the orientation of the greenhouse, North-South/East-West, design your shading so that that the area you wish to devote to the orchids that require the brightest light are on the South end/side of the greenhouse and the shading gets darker to the north end/side of the greenhouse. This assumes that you wish to grow several genera with different light requirements.

Growers should think about the type of shading that they wish to use depends on their lifestyle and habits. If you pay attention to detail by checking your light levels often with a good light meter and don't do a lot of traveling, you ,may wish to use greenhouse shade paint and a purpose sprayer to apply shading as needed throughout the year.

However if your don' want to deal with this that often, buy a shade cloth designed to provide the proper light levels for the various genera. Shade cloth comes in 6, 12 and 20 foot widths. Allow for the change in sun position during the year.

The angle of declination in Huntsville, Al is 34.5 degrees. Allow for extra shade cloth to shade the South wall of an East-West greenhouse. Shade paint may be better for the South end of a North-South green house. If you use shade paint you must check your light levels after every heavy rain or long periods of any rainfall. Light levels are to be taken at noon. Published light levels for plants are based on readings taken on the longest day of the year and do not take into account those four oak trees next to the greenhouse or lean-to type greenhouses that are on the east or West side of your house.

This type of greenhouse would be better on the South side of the house as afternoon rays are hotter(in the red part of the spectrum) than morning rays and more prone to burn foliage thn morning light. These light levels are a function of time of exposure. If trees or houses shade your green house, the plants will take a higher level of light to bloom and grow well. How much? This is debatable due to the many factors but up to about 40 to 50% is probable a good upper limit.

Most plants exposed to these increased light levels will require a cooling system in the spring through fall to keep them from burning. The following are recommended light levels in footcandles for all day exposure, taken at noon on the 21st of June:
 
Author: Tropical FX
173 Silverwood Lane
Hazel Green AL 35750
Type of Orchid Light Levels in fc Notes
Phalaenopsis
1000+
2000+ fc in peat-lite mixes for art shade phals
Cattleya
2000-3000
Vandas(strap leaf)
3000-4000
Oncidiums
2000-3500
Paphs(mottled leaf)
1000
Paphs(strap leaf)
2000-3000
Psychopsis
1200-1800
Bulbophyllum
1800-2500
Revised on: Mon, Feb 27, 2012