Cattleyas are excellent orchids for the beginners' first attempts at orchid growing. These sturdy plants can endure many of the initial mistakes we all will make, and the flowers they readily produce under adequate cultural situations are a wonderful reward for both beginner and expert alike. There are miniatures as well, which are great for those with limited space.
Cattleyas need abundant though not intense light in order to grow and flower well. About 2,000 - 3,000 foot-candles is satisfactory, and as with many orchids, the early morning sun is very important. An east window, or a south window with light shading such as a sheer curtain from the middle of February to the end of October, is very satisfactory.
Cattleyas thrive with a day temperature range between 70 and 80 degrees F. At night there should be at least a 10 degree drop, to 60-64 degrees F. This lower night temperature will help initiate flower buds and will promote stronger growth. Keeping the plants near a window will help. Cattleyas can be grown outside from June to August in a filtered light. Direct sun will burn the leaves.
Cattleyas like a humidity of between 45% and 60%. This may be attained by the use of a humidifier, or by filling a saucer with crushed rock and placing it under the plants. Then, when you water, the run off will fill the saucer, releasing humidity into the air via the crushed rock. However, make sure that the pot is elevated above the water level in the saucer.
You should water Cattleyas when the potting mix feels dry almost to the bottom of the pot. This situation generally occurs every week or so from the previous watering. If in doubt, don't water. Wait another day or two. Small plants can dry out quicker than large ones. Plants should never stand in water.
In the summer, Cattleyas potted in fir bark should be fed every second watering with a half strength solution of Peters Blossom Booster fertilizer. In the winter feeding once every three or four weeks is sufficient.
The material to be used should be a medium grade fir bark. In general, repotting should be done every 2 years in the spring. Repotting becomes necessary when the plant has outgrown its pot and the new growth reaches out over the edge, or when the potting medium has broken down. Pick a pot that is large enough to accommodate 2 or 3 years growth (1 or 2 new pseudobulbs per year). Start by gently, but firmly, pulling the plant out of its old pot. Pry out from between the roots as much of the potting material as you can. Trim off any dead roots or dead pseudobulbs, and position the plant with its oldest pseudobulbs to one side of the new pot. Then, spreading the plant roots out, fill in the space with the potting medium, gently tapping the side of the pot to settle it into place. Build up the bark until the plant rests with its rhizome on the surface, about a half-inch below the rim of the pot. Newly potted plants have a tendency to wobble, but a couple of stakes and wire will help support the plant. To divide a plant simply pull it out of the pot and cut through the rhizome between the pseudobulbs leaving three to four bulbs per division. If possible try to untangle some of the roots for each division. You may have to cut some of the roots in order to divide the plant, but this is inevitable.
Keep dry for the first week after repotting.