Proper Brassia orchid care consists of providing temperature, humidity, light, water, and nutrients that are at least similar to their natural environment. If you can optimize these aspects you can grow spectacular Brassia orchids. To determine these factors we use what we know about where they live naturally. The Brassia genus originates in Central and South America and the West Indies. Some can also be found in South Florida. They can usually be found at elevations from sea level up to 3000 feet above sea level and grow mainly in wet forests. The Brassia orchid is an epiphytic plant and grows in trees and anchors itself to the bark. They are found to grow in areas high in humidity where average day time temperatures run from 65 to 70 degrees Fahrenheit to 55 to 60 Degrees at night. From this information we can determine what the plant needs in respect to five factors above.
From average temperatures taken in these areas, you can determine that the optimal high temperature will be between 75 and 80 degrees Fahrenheit for a high temperature during growing season. During the resting season or cool season the optimal lowest temperature will be around 65 degrees Fahrenheit.
From the elevation and knowing that these grow in wet forests it is safe to say that Brassia prefer humid conditions. Lower elevations are normally more humid than higher elevations. Humidity is necessary for most epiphytic plants for them to survive during drier times by absorbing moisture from the air. Most epiphytic plants require at least 50% humidity during growing season with an optimal humidity of about 70%. If you are growing the Brassia indoors in a pot a humidity tray may be necessary.
From where these orchid plants reside you can determine the amount of light needed. Naturally growing in trees the Brassia orchid will only get direct sunlight in early morning or early evening when the sun is low enough to get under the tree canopy. During the rest of the day they will be partially shaded. Since they grow in Central and South America they are getting sun longer each day and brighter than you would get in North America or Australia which are farther north and south. So the duration of the light it gets is higher than plants found in North America. Brassia orchids grown outside of these regions will need supplemental light during spring and fall to give optimal conditions. The color of the leaves is a good indicator or the light your orchid is getting. The leaves should be a mid green color. If they begin to yellow back off on the light if on the other hand they become dark green increase the amount of light they receive. If after making these adjustments you see no change then change your fertilizer schedule to adjust.
During most of Brassia orchids growing season it will get a morning dew and a torrential rain at least once a week. So during warm growing season you will want to mist the leaves every morning. To mimic a torrential rain you will need to water thoroughly until all the media is soaked. If growing in a pot you can soak the pot in water for 15 minutes allowing the potting media to absorb the water. It is very important that there is not standing water in the pot as Brassia are highly susceptible to root rot.
In nature Brassia orchids get their nutrients from water that runs down the length of the tree or branch and in between the bark by way of the roots that are attached to the bark. Most of it is fine organic material from the parts of the tree of from bird and animal feces washed off of the tree by rain. This would be very difficult to mimic and most organic fertilizer comes with an unwanted odor. You can use fertilizer to overcome these problems. A balanced fertilizer will work best for Brassia. I propose that you use what is called a weak weekly approach to fertilizing orchids. In this case you would follow the instructions on the fertilizer package except make the solution at quarter strength. Fertilize only after watering and fertilize three weeks out of four. The fourth week use regular in order to keep the minerals from the fertilizer from building up on the potting medium. During the winter or cool months when the plant is resting only water every other week and do not fertilize. Water often enough so the plant does not completely dry out
Occasionally re-potting will be necessary. Not only will you need to do this to keep the potting medium from decomposing but also if the plant needs to be divided because new pseudo bulbs will grow each year. If potting begins to decompose or smell bad you will need to re-pot right away. Also, if you see mold or fungus developing on the medium or plant you will probably need to re-pot. Aeration in the potting medium is a must for the Brassia orchid. Epiphytic orchids are sensitive to over watering so the potting media must drain well. I prefer using a mix of sphagnum moss, charcoal, perlite, and coarse grade bark.
Caring for Brassia orchids will require you to put a little more effort than some of the other more popular orchids especially if you are growing them indoors or in northern parts of the US. You may also have more expense if a humidity tray, orchid growing lights, or even a greenhouse may be necessary to provide the proper care.