Advice
RHS Help & Advice
Growing Clivia
Cultivation
Clivia do best in bright filtered light in a conservatory or on a windowsill. Avoid direct sun in summer which may scorch the leaves. Place pots away from radiators.
Pot up in a well-drained, loam-based John Innes No 2 compost mixed with multi-purpose compost (25% by volume) and grit. Do not plant too deeply.
For flowers to form, clivias need a cool period of 10oC (50F), from November to February. After this, water lightly applying a balanced liquid fertiliser weekly until the flower buds form, then move to a well lit position with a temperature of 16oC (60F).
After flowering remove the flowers, unless seed is required, and reduce watering. Over winter water sparingly but do not allow pots to dry out.
Re-pot in early spring into a slightly larger container. Clivias flower best when well established in pots at least 20cm (8in) in diameter. Leave to grow on for several years undisturbed, top dressing annually with fresh potting mix.
Propagation
Division: Divide after flowering into containers that just accommodate the roots. Water and keep at a temperature of about 16oC (60F). Offsets can also be detached and potted up.
Seed: Harvest seed from the berries when they turn red and sow immediately. Sow singly in 7.5cm (3in) pots, using a loam-based compost (John Innes No 1) just covering the seed. Germination takes between six to eight weeks at a temperature of 21oC (70F). Grow on at 16oC (60F) once the first leaves appear.
Problems
Non-flowering is usually due to over-potting or high temperatures over the winter.
Plants will flower on short stalks if they have an insufficient cool period over the winter.