The Corsage Orchid Cattleyas are among the most commonly grown orchids, and their culture is often used as the basis for comparison with other types of orchids. Like most other cultivated orchids, cattleyas are epiphytes, or air plants. They have well-developed water-storage organs (called pseudobulbs) and large, fleshy roots. They should be potted in a porous, free-draining medium. The most commonly used are fir bark, shredded tree-fern fiber, various types of rock, processed coconut fiber and, lately, mixes based on peat moss and perlite. Keep out of cold, dry air while in bloom. L I G H T Sufficient light is important for healthy growth and flower production. PROVIDE Bright light, some sun. In the home, an east, west or lightly shaded south window. In a greenhouse, about 30 to 50 percent full sun. Under lights, four 40 watt fluorescent tubes and two 40 watt incandescent bulbs directly over plants. Plants should be naturally erect, without need of much staking, and of a medium olive-green color. Dark green, limp foliage indicates too little light. T E M P E R AT U R E Mature plants need a 15 to 20 F difference between night and day. PROVIDE Nights of 55 to 60 F; days of 70 to 85 F. Cattleyas can tolerate temperatures up to 95 to 100 F if shading, humidity and air circulation are increased. Seedling cattleyas need temperatures five to 10 degrees higher than mature plants. W AT E R Mature plants must dry out between waterings. Seedlings need more constant moisture. H U M I D I T Y Cattleyas need 50 to 60 percent. In the home, place on trays over moistened pebbles. In greenhouse, use a humidifier if conditions are too dry. F E R T I L I Z E R Must be provided on a regular basis because most potting media have little. PROVIDE The exact fertilizer you use will depend on the mix in which your plant is growing. A good general rule is to use a balanced (10-10-10, 12-12- 12 or similar ratio) fertilizer “weakly, weekly.” That is, fertilize every week at one quarter to one half of the recommended dilution. P O T T I N G Should be done every two to three years in spring before mix loses consistency (breaks down). Pot firmly in media that have good aeration and ample drainage, allowing enough room for two years’ growth.