Cattleya

Light is the most important factor in growing and flowering Cattleyas, whether in a greenhouse or in the home. They can receive direct sun indoors in a South, East, or West window, or direct sun in a greenhouse. Leaves should be a chartreuse-green color; pseudobulbs erect and require no staking.

• In a greenhouse, 50%-70% full sun or about 32,250-53,750 lumens (3,000-5,000 foot-candles) is ideal. Southern climates below the 37th parallel will need to use shade cloth. Northern growers can expose some species to full sun with no consequence.
• Indoors, Cattleya should be placed in any window (ideally south-facing) that gets more than 4 hours of direct sunlight to bloom. You cannot sunburn a Cattleya indoors.
• If grown under lights, Cattleya should receive more than 3000 lumens of light to bloom and grow.

Temperature depends on the hybrid/species, but in general, Cattleya are happy with 55F-72F (12.7C-22.2C) nights and 70F-85F (21.1C-29.4C) days. Seedlings should have night temperatures a few degrees higher. Higher day temperatures can be tolerated (up to 95F (35C) if humidity, water, air circulation, and shading are increased.

• If growing indoors, there is no need to worry about temperature; room temperature all the time is fine.

When thinking about water for epiphytes like Cattleya, you must keep in mind that they like to have quick wet/dry cycles. Cattleya like to go dry between waterings but like to be immediately watered when their media hits dryness. Always use lukewarm water, as water temperature below 50F (10C) may injure plants, as will hard water or water softened by the addition of salts.

• If growing in a greenhouse, you should adjust your watering so that the plants have time to dry before the next watering. Mounted cattleyas may require additional watering in warm/hot conditions.
• Indoors, Cattleya should be grown potted, and watered from the top. Otherwise they can be taken to the shower or sink and be watered, drip dry, then be placed back. The frequency will depend on how fast it takes for the media to dry in your conditions.

Humidity for Cattleya is a bonus but is not necessary for growing these well. Remember that humidity is an anti-dryness factor. If you raise the humidity, the plant will be slightly more robust, but not incredibly so.

• In a greenhouse, air should always be moving around the plants to prevent fungal or bacterial disease, especially if high humidity or cool temperatures exist.
• Indoors, as long as the Cattleya are well-watered and frequently watered, you do not need to worry about humidity.

Fertilize on a regular schedule. Use ½ to ¼ strength of a normal dose regularly when plants are actively growing. A higher nitrogen formulation (such as 30-10-10) is recommended during active growth. In autumn, or after growth slows, fertilizer should be reduced or eliminated for the winter. Some growers use a high-phosphorus formula in the spring to promote flowering.

Potting is necessary when you first get the plant, if the rhizome of the plant protrudes over the edge of the pot, or if the potting medium starts to break down and drain poorly (usually after 2 to 3 years). If you see new roots or shoots just starting to grow, that is the best time to repot. Otherwise, you will have to wait until after flowering. Mature Cattleya are usually potted in coarser potting material than are seedlings. Until a plant has at least six mature pseudobulbs, it generally should be repotted into a larger pot and not divided. If dividing a plant, three to five pseudobulbs per division are required. Select a pot that will allow for approximately two years of growth (usually a 2-3 inch (5–8 cm) larger diameter pot) before crowding the pot.

• If growing in a greenhouse, use medium to coarse orchid bark mix. No sphagnum is necessary, except for perhaps the smallest of seedlings.
• If growing indoors, you will want to mix about ¼- 1/3 of sphagnum to either fine or medium grade orchid bark mix (which is bark+perlite+charcoal). Alternatively, planting into 100% treefern fiber works well with plastic pots indoors.

Cattleya usually bloom once a year, though through hybridization, some hybrids can bloom multiple times a year. Most are fragrant, unless there are certain Laelia or Sophronitis in the background. Cattleya are the most succulent of the orchids (besides Eulophia), and you will also see other closely related genera lumped in with them for their ability to be hybridized or their similarity in care.

• Cattleyas for the Beginner

Further information can be found on the Cattleya genus page.

Best orchid care practices are also provided for watering, repotting, and fertilizer types. There are also detailed discussions of growing orchids indoors, outdoors, or in greenhouses.

For more information on genus name changes, see Taxonomy.