Anne Swithinbank’s Masterclass

Q My Clivia miniata flowered well, but has been growing in the same pot for several years and the compost has gone dusty. Should I repot it and, if so, when and how? Is it best to cut off the old flower stems?

Annette Evans, Stroud, Glos

A Clivias (Natal lilies) are among my favourite indoor plants due to their deep-green, strappy leaves and clusters of yellow-centred, bright-orange flowers opening in March and April, or August. There are cultivars available with lightly scented yellow or apricot-coloured blooms and some with variegated foliage. Needless to say, the more unusual kinds tend to be expensive.

Originally from wooded areas of South Africa, clivias remain green and healthy in the soft light of a north or east-facing window. Harsh light causes leaf scorch and yellowing. Plants grow actively in summer and autumn, but prefer drier, cooler winter conditions with a minimum of around 50°F (10°C). I love the moment when new flower buds appear pale green between the leaves in late winter, a signal to water more normally just as the compost surface dries out. A monthly well-balanced liquid feed from spring to autumn is enough to keep established plants healthy.

Clivias make clusters of growth attached to fleshy roots, and can live contentedly in the same pot for many years until the compost deteriorates or the leaves of pot-bound plants turn yellow, signalling time for action.

Now, after flowering, is a good time for repotting, but first note whether the plant consists of one crown or several. You could move the whole lot into a larger container for multiple flower spikes or divide crowns of growth into ones or twos for smaller pots. They perform equally well in plastic or clay.

After blooms have faded, flower stems remain green to support developing berries. These take more than a year to ripen, but in my experience leaving them on the plants does not affect their ability to flower. If no berries form, they gradually wither and if seeds are not wanted, you can cut them down at any time.

Harsh light will cause leaf scorch and yellowing, so place clivias in a north or east-facing window This picture was taken of my clivias one April. They had been moved briefly to the greenhouse, but live mainly in the soft, filtered light and cool winters to be found in my north-facing office