A dwarf, hybrid plant with fruit suitable for preserves and marmalades.

Citrus are not demanding plants, but a conservatory or frost-free glasshouse is a must for anyone wanting to grow them well. They do not make happy house plants in winter, when light levels and humidity are usually too low, and centrally-heated rooms indoors are usually too hot. For healthy plants, provide a winter minimum of 13°C (55°F) for calamondin oranges.

Growing citrus

During summer, stand citrus plants outdoors in a sunny, sheltered spot such as a south-facing patio. Water regularly and feed weekly with a summer citrus fertiliser. As the weather cools in autumn, bring the pots into a conservatory or glasshouse, reduce watering and stop feeding. A few leaves may yellow and drop from the initial change of environment. Excessive leaf drop suggests overwatering and either too high or too low a temperature. If in doubt, let the compost dry slightly between waterings. Repot only in spring, using a John Innes No 2 potting compost with extra grit or sharp sand. If the roots are not congested, simply topdress by replacing the top 5cm (2in) of compost.

Pollination

Fragrant white flowers are borne on one-year-old wood from December to February. Warmth and humidity encourage good flowering. Flowers are bisexual and self-pollinating, so don't require artificial pollination. Fruits take almost a year to develop fully. Thin fruits on younger plants.

Pruning

Remove congested growth in early spring, and pinch out shoot growing tips in summer. If renovation is required prune back by two-thirds in early spring.