Cultivation notes

Clivia are frost tender and can be damaged by temperatures below 5°C (40°F). They should be grown as a houseplant, in a conservatory or warm greenhouse and do best in bright, filtered or indirect light. Avoid direct sun in summer, which may scorch the leaves, and place pots away from radiators or other sources of heat.

Pot up in well-drained, loam-based John Innes No 2 compost mixed with multi-purpose compost or additional leaf mould and grit, although any good potting medium should be satisfactory. Do not plant too deeply – the neck of the bulb should be above soil level.

For flowers to form, a cool period of 10°C (50°F) is needed from November to February. After this, water sparingly, applying a balanced fertiliser weekly until the flower buds form; then move to a well-lit position with a temperature of 16°C (60°F).

After flowering, remove spent flower stems near the base, unless seed is required, and reduce watering. Water sparingly through winter, but do not allow the containers to dry out.

Repotting, where necessary, can be carried out in early spring using a slightly larger container. Clivia flower best when well established in containers at least 20cm (8in) in diameter. Leave to grow on for several years undisturbed and top dress annually with fresh potting compost.

Book references:

Clivias by Harold Koopowitz (Timber Press 2002, ISBN 0881925462)

Grow Clivias: A guide to the species, cultivation and propagation of the genus Clivia by Graham Duncan (National Botanical Institute, Kirstenbosch 2002, ISBN 1919684379)

These books are also made available through the RHS Lindley Library.

Pruning and training

Apart from deadheading, no pruning or training is required.

Propagation

Clivias can be propagated by division after flowering or from seed:

Division

• Wash old compost away from fleshy roots, which are easily damaged
• Try pulling the plants apart rather than cutting them as this does less damage to the roots, buds or shoots
• Do not over-pot – place each section into a container that just accommodates the roots
• Keep at a temperature of about 16°C (60°F)
• Water well and mist divisions until they are established
• Strong-growing offsets with good root systems can also be detached and potted up

Seed

• Harvest seed from the berries when they turn red and sow immediately without allowing the seed to dry
• Sow seed individually in 8cm (3in) containers using a loam-based compost such as John Innes No 1, just covering the seed
• Seeds germinate in six to eight weeks at a temperature of 21°C (70°F)
• Grow on at 16°C (60°F) once the first leaves appear
• Seedlings are likely to take three to four years to flower and may vary in colour

Cultivar Selection

Clivia miniata AGM (Natal lily): With strap-shaped leaves up to 60cm (2ft) long. From spring to autumn, it bears large flower umbels of up to 20 tubular- to funnel-shaped red, yellow or orange flowers. These flowers 5-7.5cm (2-3in) long.  Height and spread: 45cm (18in) by 30cm (1ft).

C. miniata AGM 'Aurea' (golden Natal lily): Has yellow flowers. Otherwise similar to Clivia miniata.

C. miniata var. citrina AGM: With pale-lemon flowers. Otherwise similar to Clivia miniata.

C. nobilis AGM: Strap-shaped leaves 45cm (18in) long and umbels of 40-60 narrow, trumpet-shaped red and yellow flowers, 2.5-4cm (1-1½in) long, tipped with green. Blooms are borne in spring and summer. Height and spread: 40cm (16in) by 30cm (1ft).

Links

RHS Find a Plant

Problems

Clivia are generally trouble-free, suffering few pests and diseases.

However, conspicuous tufts of white, waxy wool appearing on the leaves indicates an infestation of mealybug, which may be troublesome. Slugs and snails can also cause damage to flowers and leaves.

Non-flowering can be due to:

• Plants being over-potted (too large a container too soon)
• Plants kept at too high a temperature during winter
• Insufficient water when in active growth may also lead to the flower buds failing to develop and dieback of foliage tips

Note that juvenile plants may take some years to reach flowering size

Yellowing of foliage may be due to:

• Inadequate feeding
• Overwatering that leads to waterlogging. To check, knock the plant out of its container. Any dead or rotten roots should be cut away and sour, waterlogged compost replaced
• Underwatering

Brown patches on leaves may be due to scorching. This can occur when light is refracted through windows or water droplets collect on leave surface.

Where plants flower on short stalks and the blooms are hidden by foliage, the cause is likely to be an insufficient cool period over the winter. From November to February keep plants at a temperature of 10°C (50°F).

Plant toxicity

All parts of Clivia miniata and its cultivars may cause mild stomach upset if ingested, and the sap may irritate skin.