Cymbidium have highly decorative flower spikes and are one of the least demanding indoor orchids. To flower well, the plants need a distinct temperature drop between day and night during mid- to late summer.
Common name Cymbidium
Botanical name Cymbidium
Group Houseplant or greenhouse/conservatory plant
Flowering time Mid-autumn to mid-spring
Planting time Re-pot in mid-spring after flowering
Height and spread 25cm-90cm (10-36in) by 30-90cm (12-36in)
Aspect Bright light, shade from direct sunshine in summer
Hardiness Tender, minimum 8-10°C (46-50°F).
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.