Culture
Orchids in general grow best in greenhouses where temperature, humidity and light can be controlled. As houseplants, cattleyas usually perform best on east window sills, but also perform well on shaded south or west window sills, with growing conditions that include (a) temperatures at 70-85° F in daytime and 55-60° F at night, (b) significant humidity (50-60 % - set pot on moist gravel tray and mist in morning), (c) bright light with some protection from sun during the heat of the day, and (d) open rooting compost (e.g., coarse redwood or fir bark, epiphytic orchid mix) that facilitates circulation of air and water. Water thoroughly with tepid water in mornings only (helps prevent root rot). Place potted plant in a sink and allow water to flow freely through the potting medium and foliage. Water mature plants one time per week (more often in the heat of the summer) and allow plants to dry out between waterings. Fertilize on a regular schedule by application, after watering, of a balanced fertilizer at the rate of twice monthly at half strength or weekly at quarter strength. Repot as needed (approximately every two years) in spring or just before new roots sprout from the rhizome, using a coarse, fir bark based orchid potting medium. Repotting is needed when the rhizome of the plant protrudes over the edge of the pot or when the potting medium breaks down and drains poorly. When dividing the plant, retain three to five of the younger pseudobulbs (stems) and place the cut rhizome against the side of the pot.
Noteworthy Characteristics
Cattleyas are popular and easy-to-grow orchids. They are epiphytic (non-parasitic plants that grow on the trunks and branches of tropical/sub-tropical trees without taking water or nourishment therefrom). Cattleyas wrap their roots around branches for stability. Nourishment comes from the air, water and decaying plant matter. Plants grow from pseudobulbs (1-3” thick) which are food and water-storage organs. Cattleya orchids are one of the most popular groups of orchids in cultivation, with over 50 species and literally thousands of hybrids. Plant varieties typically grow from a few inches to 2’ tall or more with leathery, oblong to broad obovate leaves that are generally dull green. Unifoliate types have one leaf and bifoliate types have two leaves. Thick fleshy roots are covered with velamen, a spongy, water-retentive material. Showy flowers (3-lobed to entire lips) appear on naked stems in a variety of colors except blue. Flowers typically last 4-8 weeks. Additional common names include corsage orchid or queen of orchids. Cattleyas are native to Central and South America from Mexico to Paraguay and Argentina.
Genus name honors William Cattley (d. 1832) of Barnet, England, a wealthy patron of botany and an ardent collector of rare plants.
Problems
Slugs, snails, thrips, scale and mealy bugs may be problematic. Watch for spider mites.
Uses
Potted plants for sunrooms and larger window sills. Plants may be taken outside in summer under trees, but never placed in direct afternoon sun.