The cattleya group is known for large, showy and sometimes fragrant flowers. Some of the most stunning orchids in cultivation are cattleyas, with huge flowers that can measure 8 inches across and come in a wide variety of colors and patterns. In the wild, there are several dozen species of cattleya, but it's unlikely you'll find any of these at local garden centers. Because of their ease of growth and sheer beauty, cattleyas are the most hybridized of all orchids, and there are thousands upon thousands of registered hybrids.
When shopping for a cattleya, consider a clone awarded by the American Orchid Society.
The cattleya orchids like bright light and will not flower without plenty of light. They can even be acclimated to some direct sunlight, although you should avoid direct summer sunlight. In the right light conditions, the leaves are apple green. Darker leaves can indicate too little light, while yellow or brown leaves can indicate too much direct sunlight.
Watering Cattleya Orchids
Cattleya is sympodial orchids that grow from an underground rhizome. They typically send up new pseudobulbs in the spring. Water heavily during the growing season, but do not allow them to sit in water. Cut water back when the flowers begin to emerge from their sheaths--water in these sheaths will rot the immature flowers. A well-watered cattleya will have fat lead pseudobulbs.
During the growing season, fertilize with a weak orchid fertilizer weekly (weakly weekly, as the growers say).
During the rest period, fertilize every other week.
Most cattleya produces one new flush of growth annually, and each new pseudobulb should produce flowers that same growing season, often in late summer or winter. Some of the hybrids might produce two blooms annually. When a plant goes into flower, reduce watering to prevent rotting the flowers.
Emerging cattleya flowers are protected by a thin sheath that emerges from the center of the leaf.
Potting and Repotting Cattleya Orchids
Cattleya grows by means of a branching, creeping rhizome with thick, clinging roots. Repotting is stressful, and a plant will usually take a season to recover, so only repot when necessary. They will do well in most orchid mixes, including pine bark, clay pellets, perlite, charcoal, or any well-draining medium. When repotting a cattleya, make sure there is enough room for the rhizome to produce at least two new pseudobulbs before it hits the edge of the pot. Typically, repotting is done in spring, at the beginning of the growing season. Cattleya can also be slab-mounted on tree fern or logs.
Cattleya are not difficult plants, and their flowers are incredibly rewarding. Depending on the species, they may produce just a few showy flowers or bunches of smaller, waxy flowers. Not all cattleya flowers are fragrant, so ask your grower if that's a priority. The biggest mistake most people make with cattleyas is not supplying enough light for the plant to bloom well and/or overwatering. Watch the pseudobulbs—a plump lead pseudobulb indicates a well-hydrated plant.