Ensure good light levels all year round, especially in winter. If the plant is kept outdoors in summer, shade it from midday sun.
Cymbidium prefers cooler growing conditions than some other tender indoor orchids. Provide winter growing temperatures between 10-14°C (50-57°F). Keep the temperatures below 30°C (86°F) in summer to prevent damage to the plants.
Plants can be kept outdoors from mid- to late summer (often June to September). However, gradually acclimatise the plants to outdoor conditions in order to prevent leaf scorch from cold temperatures or direct sun.
Flower spike initiation takes place in mid- to late summer, when plants require good light and a distinct drop between day and night temperatures. Placing the plants outside helps to provide such conditions.
To prevent bud-drop, keep the temperature below 15°C (59°F) during flower spike development. Wait until the flowers have opened before moving the plant into a warmer environment for display purposes.
Support developing flower spikes with a bamboo cane. Flowers generally last for six to eight weeks. Once the blooms have faded, cut down the flowered stem to the base.
Cymbidium needs moderate watering during spring and summer, depending on the conditions. Water from above, making sure that excess water can drain away. Do not allow the plant to sit in water. Let the compost dry out a little before the next watering. Plants placed outdoors or in the greenhouse may need more frequent watering in hot weather. Outdoor plants may only need occasional watering if the weather is wet. Reduce watering to weekly or fortnightly in winter.
Apply half-strength general liquid fertiliser every third watering in spring and switch to a high potassium specialist orchid fertiliser in summer. Stop feeding altogether, or feed only occasionally in winter, using half-strength general liquid fertiliser.
Re-pot in spring (after flowering) every two to three years. Use specialist cymbidium or other free-draining compost. Re-pot into a container just slightly larger than the roots of the plant, as Cymbidium flowers better if it is slightly pot bound.
Orchids: indoor cultivation
Divide plants at re-potting if they have become over-large, or if some of the pseudobulbs (swellings at the base) have died and turned brown. Select divisions with three healthy pseudobulbs, discarding older or shrivelled material. Divisions will take about two to three years to flower again. For more information, see the propagation section under orchids: indoor cultivation.
New hybrids are produced every year, but most of these are sold unnamed. Only specialist orchid nurseries offer named species and hybrids. New introductions tend to be easier to grow, but for the keen grower, here are some species to try:
Cymbindium erythrostylum: Compact with white flowers and red lip.
C. tracyanum: Tall, arching stems of yellow-green flowers boldly striped brown.
C. tigrinum: Compact with hanging clusters of olive-green to yellow flowers with purple-marked lips.
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