Citrus × sinensis or Orange Tree is a citrus fruit that has been grown in China for at least 2,300 years. It was brought to Europe by the Portuguese in the sixteenth century.
A phylogenetic study showed that it is a cross between mandarin (Citrus reticulata) and grapefruit (Citrus maxima).
This is a slightly rustic tree (short frost down to -8 °C) but it is better to bring it indoors in the winter. Previously, buildings called orangeries, were especially designed for overwintering citrus trees.
It is a beautiful tree that can bear fruit in colder regions.
The fruit, called orange, is eaten fresh or juiced.
The orange tree is a tree or bush with a single trunk and spherical crown, reaching a height of 7.5 to 15 m.
Foliage is evergreen. Leaves are dark green, leathery, elliptic to ovate, 6.5 to 15 cm long and 2.5 to 9.5 cm wide. They often have narrow wings on the petioles.
The flowers are white and pleasantly scented. They are produced individually or in groups of up to 6 flowers. They are about 5 cm wide, have 5 petals and yellow 20-25 stamens. An essential oil or absolute, called neroli, is extracted, which is used in perfumery and food.
The fruit is globose to oval, measuring 6.5-9.5 cm wide. It becomes orange or yellow when ripe. The skin of the fruit contains many small glands. The flesh is juicy and sweet, generally divided into 10-14 segments and its color varies from yellow to orange to red. Hundreds of cultivars have been developed, which are grouped into four broad categories according to geography (Mediterranean oranges, Spanish oranges) or characteristics (blood oranges, navel oranges).
Fruit ripening takes 9 to 12 months.
Blood orange, navel orange , naranja, orange, sweet orange, Valencia orange
Citrus: from the Latin citrus (citrus, citrus tree)
Sinensis: from the Latin sinae (from China)
Orange: from the Sanskrit nāraṅga (orange tree)
Citrus aurantium var. sinensis
USDA zone 9, -8 °C but over very short periods. It is best to overwinter it inside, out of the frost.
Seed, cuttings, grafting and layering. Grafting ensures plants with the same characteristics as the parent plant and generally produces more fruit than plants propagated seed or cuttings.
Flowering and fruiting takes place 3-5 years after sowing or planting.
- collect seeds from vigorous plants and mature fruit
- clean the seeds and let partially dry
- sow in moist sowing mix
- 20-30 °C
- germination time: 5-50 days
Any soil, well drained
Water till saturation and then water again when the rootball dries. This prevents the roots from rotting.
Universal or specialized for citrus and olive liquid fertilizer, once a week during the growing period, once a month in winter.
In summer, the plant may be grown outdoors in full sun and sheltered from the wind. Overwinter in a cool room at 5-10 °C.