Some general guidelines for the cultivation of most members of the Catlleya Alliance:
The Cattleya Alliance encompasses many well known Genera such as; Cattleya, Epidendrum, Encyclia, Laelia, Sophronitis & Brassovola, just to name a few. What many people do not realize is that it also contains many more obscure Genera like; Alamania, Arpophyllum, Barkeria, Neolauchea, Psychilis, Quisqueya, & Tetramicra as well as many others.
The guidelines below are necessarily general since there are far too many variables in the habitats of the many genera & species to allow a more precise outline of their culture. If you have questions about certain plants you may call, write, or email me.
Temperature: As a general rule, majority of the species will do well with a minimum night temperature of 55-60F and it is also customary to provide a minimum 15 degree rise in daytime temperatures. Summer daytime highs of up to 90F are seldom a problem as long as sunburn doesn't occur (see "light", below). There are also a number of species/genera that are cooler growers although they too can often be accommodated when one realizes that many of those may only need the cooler weather in the winter, or a seasonal cooler/drier rest.
Light: For the majority, assume a fairly high light level. Most often, growers will provide 2500-3000 foot-candles, roughly double the level given to Phalaenopsis. Many of the Hybrids and some of the dark-flowered species will produce somewhat purple-tinted (colored with anthocyanin) foliage when exposed to very bright light and sometimes when grown too cool & bright. A little tinting is fine but a lot of foliage color is an undesirable.
("Sunburn" is a condition that most any plant can acquire. It is manifests itself as a brown/black patch that most often develops on the flat surfaces of the leaves, on the sides most directly facing the light source. It is caused by the internal tissue temperature rising to a point where it causes tissues' death. All high-light plants can be "overdone" during the transitions between seasons, with the lengthening of the days or even on a clear, bright winter day following a dark/dreary autumn. Too high of an air temperature along with excessive light levels will increase the chances of problems. Additional air movement sometimes will help prevent leaf overheating and still allow the plant to receive bright light levels.)
Water: Here's a somewhat easier topic; When the foliage is thick & leathery and the plant has substantial pseudobulbs = assume that the plant must dry out considerably between watering. When the foliage is thin textured and there are no pseudobulbs = assume that the plant must seldom dry excessively and that the plant may want less light than others. When you see plants with very reduced leaves, or those with "low profiles" such as "pencil-like" (terete) leaves, they are oftentimes the most light loving of all.
Humidity: The requirements here will vary considering the genera & species involved. Most often, ranges or 50-70% are preferred. Typically this family of orchids is somewhat forgiving with regards to Humidity, the exceptions being some of the more "cloud forest" oriented species which will, of course, prefer it uniformly higher (Sophronitis, Nanodes, Diothanaea, Neocogniauxia).
Media: Traditionally, these plants are grown potted and usually in a basic bark-based mix. Nearly all of the genera & species are epiphytic (growing on other living things), therefore they will grow just as well or possibly even better when mounted. Since we are also discussing many of the less well-known genera too, let it suffice to say that many of the more obscure ones may do best when mounted to slabs of cork, tree-fern, or other similar strata.
Fertilizer: Most traditional recommendations work fine here = Balanced fertilizer(20-20-20, 18-18-18,etc.) mixed 1/2 strength, applied every couple to third week. A the beginning of the spring, a higher nitrogen-type fertilizer may be given, if needed. As in many other Genera, do consider that many of the cooler, moister-growing, "Cloud Forest" types seem to prefer a more dilute and less frequent feeding schedule that their more robust lowland counterparts.