Compost and potting
Citrus plants are best grown in well-drained pots in a loam-based compost with either grit or bark chippings to aid drainage. Good drainage is very important. The optimum compost/soil pH is 6.5.
Citrus should be re-potted once a year or when the plant becomes pot-bound. They can be re-potted at any time of the year, but preferably in early spring.
Light and temperature
Citrus trees grown in the UK require as much sunlight and ventilation as possible.
Watering and feeding
Water thoroughly, but allow the compost to dry out almost completely before re-watering. They do not like over-watering due to their sensitive roots, so in winter they should only be watered when the soil/compost is almost dust dry.
In spring, during the growing season, they will need regular feeding with a citrus specific feed, such as Citrus Focus. They can also be fed in the winter, but not so frequently.
Citrus trees do not like pruning. If required, prune lightly in mid-spring when the sap starts to rise. Never prune in winter. Like many subtropical trees they need time and heat to heal the wounds. Prune above an active bud, which is normally above a leaf node.
Flowering and fruiting
Citrus trees produce small cream coloured flowers with a very distinctive fragrance. If the temperature is on the low side, the trees may not flower or may not be able to ripen their fruit. When the fruit is ripe you need to take if off the tree.
Pests and diseases
In the UK, citrus trees may be affected by various scale insects, whitefly or greenfly and red spider mites. An ideal way to kill any of these insects is regular spraying with SB Plant Invigorator, a contact insecticide that can be used even during the harvest period.