Pronounced: KAT-lee-ah
These South American orchids are familiar to many as corsage orchids or in wedding bouquets. Plants vary from 10 cm in height to almost a meter in some cases. The flowers are large and come in many colors and in some cases with contrasting lips or multicolored petals (splash petals). More difficult to grow well than some orchids, they are tough, resilient plants which will survive some mistakes and once growing well provide rewarding displays.
Healthy Cattleya start with healthy roots:
- Pot in a coarse medium. Fir bark mixtures are best, with 1.5 to 2.5 cm chunks of bark, perlite and charcoal.
- Repot when medium starts to decompose or new growths have reached the edge of the pot. Repotting must be done hile roots are growing (green tips on roots, or new roots just emerging from plant). Avoid repotting if new roots are 0.5 cm to 5 cm in length as roots may be lost if damaged at this size.
- Remove old medium if it is loose and any rotting roots; choose a plastic pot that will allow for two years (typically 2 to 4 growths) growth in the new pot.
- Roots should dry out somewhat between watering. When the plant is actively growing, water when medium has just begun to dry out but is still somewhat damp. When the plant is dormant, typically in winter, do not water until medium is almost completely dry. Water thoroughly, with a volume of water at least equal to that of the pot.
- Do not use water softened in salt-consuming water softeners. Low mineral water is preferred, such as naturally soft water or rain water. If hard water is used, water very heavily to flush minerals.
- Fertilize weakly and frequently with a balanced fertilizer. One-eighth to one-quarter strength recommended by manufacturer for house plants every week while the plant is in active growth (spring and summer) and not at all while plant is dormant (typically autumn and winter).
Healthy leaves produce more and bigger flowers:
- High light levels are appropriate. Leaves should be a light green, not yellowish (too much light) or dark green (too little light). They should be firm, not long and floppy (more light needed). Any more red than the slightest blush on the leaves indicates too much light.
- Four hours of sunshine on a windowsill (West or South) or 15-30 cm under an eight tube fluorescent fixture or under an HID sodium or metal halide lamp. Laelia pumila hybrids do not require as much light.
- Leaves and newest pseudobulbs should be firm; if wrinkled, check roots for rot, and repot if necessary. High humidity (such as enclosing the plant in a plastic bag) will aid recovery if most or all of roots lost, but be careful of rot.
- Cattleyas do best with 50-60% humidity but will grow and bloom, although more slowly and with smaller flowers in lower humidity. Use humidifier to raise humidity – humidity pans and misting minimally effective. Enclosing plant growing areas is effective but ensure fresh air and air movement to avoid mold and rot.
- Grow Cattleyas in intermediate temperatures with 14°C minimum winter nights and 29°C summer day maximum. Ensure 6-12°C day/night difference to aid flower formation.
Cattleyas usually bloom annually although some bloom spring and fall or frequently through the year:
- Orienting plant with new growths towards light source results in best display. Windowsill growers may need to stake new growths as they may grow too horizontally as a result of growing towards the light source.
- Flowers typically last about two weeks.
- Cattleyas often produce a “sheath” of leaf-like material in the center of the growth to protect the buds as they form. In humid areas or when you see the buds begin to swell in the sheath, gently open the sheath to ensure that moisture does not form and cause rot or trap the buds.
