Sweet Orange (Citrus sinensis)
At a glance
- Lifecycle
- Perennial (hardy)
- Exposure
- Full sun
- Frost limit
- −6.7 °C
Cultivation
Prefers a moderately heavy loam with a generous amount of compost and sand added and a very sunny position. The sweet orange is widely grown for its edible fruit in warm temperate and tropical zones, there are many named varieties. The young growth in spring, even on mature plants, is frost-tender and so it is best to grow the plants in a position sheltered from the early morning sun[K]. The flowers are sweetly scented. Plants dislike root disturbance and so should be placed into their permanent positions when young. If growing them in pots, great care must be exercised when potting them on into larger containers.
Propagation
The seed is best sown in a greenhouse as soon as it ripe after thoroughly rinsing it. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least three growing seasons before trying them outdoors. Plant them out in the summer and give them some protection from the cold for their first few winters outdoors. Cuttings of half-ripe wood, July/August in a frame. Layering in October.
Edible uses
Fruit - raw. Sweet and delicious. The rind of the fruit is often used as a flavouring in cakes etc or made into marmalade. Flowers - cooked as a vegetable or made into a tea.
Medicinal uses
Citrus species contain a wide range of active ingredients and research is still underway in finding uses for them. They are rich in vitamin C, flavonoids, acids and volatile oils. They also contain coumarins such as bergapten which sensitizes the skin to sunlight. Bergapten is sometimes added to tanning preparations since it promotes pigmentation in the skin, though it can cause dermatitis or allergic responses in some people. The fruit is appetizer and blood purifier. The fruit juice is useful in the treatment of bilious affections and bilious diarrhoea. The fruit rind is carminative and tonic. The dried peel is used in the treatment of anorexia, colds, coughs etc.
Material uses
A semi-drying oil obtained from the seed is used in soap making. An essential oil from the peel is used as a food flavouring and also in perfumery and medicines.
Habitat
Original habitat is obscure, possibly an introgressed hybrid of C. maxima x C. reticulata.
Native range
Original range is obscure, possible Asia in southern China and Vietnam.