Native of warm climates, citrus can be grown in cooler climates if they can be kept frost-free during winter.
Their flowers appear on one-year-old shoots in late winter, and nine to twelve months later the fruit will ripen. Because their fruits take so long to mature they can flower and fruit at the same time.

Site and soil

Citrus should be planted where they will receive the most sunlight, especially in cooler climates.
While some species are comparatively more tolerant of cold, none are fully hardy and should be brought into a frost-free place during winter.

Buying and Planting

When buying, select a plant that has a balanced framework of branches and a strong graft union.
In cooler climates, it is usually best to grow them in pots. That way they can be moved around to make the most of warmth and frost protection.

Plant care

Citrus respond well to regular feeding. The majority of the flowering and fruit ripening happens in winter, when they need a balanced fertilizer. During summer a high nitrogen fertilizer is preferred, as it is a period of leaf growth. Specialist citrus feeds for spring/summer and autumn/winter are available and worth using.
Keep citrus plants well watered during summer. During winter, allow the compost to dry out slightly between watering.
Pot the plants annually in early spring, or top-dress with fresh compost.

Training & Pruning

The main pruning period is late winter, just before plants come into growth.
If a plant bears too many fruits, it may need to be thinned out – a plant 1m (3ft) tall should have no more than 20 fruits. Kumquats, however, don’t need thinning.

Harvesting

Once fully grown the fruit develops a rich skin color, signifying they’re ready to pick.