Mandarin Tree - Citrus reticulata Keraji

The Keraji Mandarin Tree (Citrus reticulata) is one of the hardiest mandarin trees, a well-established bush that can withstand temperatures as low as -12°C (10.4°F). This Japanese variety is also highly appreciated for its fruits, which resemble large, flat mandarins that are easy to peel. These fruits ripen in winter, more or less late, even in relatively cool climates. They then reveal an astonishingly balanced acidic and sweet flavor.This citrus tree is particularly well-suited for cultivation in open ground in regions less favorable for the growth of these plants. Its compact habit allows it to be cultivated for many years in a large pot on the terrace, protected from frost in winter.

The Keraji Mandarin Tree is a compact, spiny bush with a dense and spreading habit, belonging to the Rutaceae family. It is a Japanese horticultural hybrid dating back to 1948, widely cultivated on Kikai-Jima Island. It was previously known as Citrus nobilis Lour. subsp. Suntara var. kagoshimensis.

This small tree reaches a height of 2m (7ft) and spreads about 1.50m (5ft). Cultivated for its surprisingly flavored fruits, this mandarin tree blooms abundantly in April-May. It produces small white flowers with a pleasant neroli scent. These flowers give way to flattened fruits with an average diameter of 6cm (2in), reminiscent of satsuma mandarins. The relatively thin skin of the fruits starts off green, then turns yellow and eventually orange, with a slightly rough texture. The amber to orange, translucent and juicy pulp of the fruit is filled with numerous seeds. Its flavor evolves with the ripeness of the fruit. Similar to lemon in November, it becomes more aromatic and sweeter throughout winter, reaching a perfect balance between acidity and sweetness in February. The fruits are harvested from November to March. The evergreen and aromatic leaves of this citrus tree are lanceolate and shiny green.

These fruits have a long-standing culinary tradition in Japan. They are used as fresh fruit and in cooking as a substitute for lemon when still green. It is also a beautiful ornamental bush, with enchanting spring flowering. Although relatively hardy for a citrus tree, it should be grown in a sheltered position, as its fruits, which are best in late winter, are susceptible to frost.

Like all Citrus trees, the Mandarin Tree contains essential oil pockets in its leaves, flowers, and fruits, which are often visible to the naked eye. These can be extracted through distillation (flowers and leaves) or pressing (peel) to obtain essential oil with sedative properties, which helps combat stress and insomnia. The fragrance of the essential oil is described as sweet and floral, and is particularly liked by children.

Most citrus trees thrive in open ground in Mediterranean coastal regions, where they can enjoy the necessary year-round warmth. However, to bear fruit successfully, they require an adequate supply of water and nutrients. The Keraji Mandarin Tree is relatively hardy and can lose its leaves at -10°C (14°F), but a well-established specimen will recover without any problems in spring, although fruiting for the year may be compromised. This hardiness only applies when the frosts are brief, the bush is sheltered from cold winds, and temperatures rise significantly during the day. It is a self-fertile bush, meaning that a single individual is sufficient for complete pollination and fruiting.