Orixa japonica - Japanese orixa

The Orixa japonica is a bush that is as classic in Asia, where it is used as a hedge plant, as it is unknown in our region. Of medium size, with a very spreading habit, it is mainly ornamental due to its foliage of a beautiful, highly glossy green, which gives it a tropical appearance. While its spring green flowering is quite insignificant, its foliage turns a pale yellow in autumn, which can harmoniously blend with brighter colours. Hardy enough to be planted in most of our regions, it is relatively easy to cultivate and requires almost no maintenance. An interesting rarity to add an exotic touch to a plant bed.

With only one species, the Orixa belongs to the Rutaceae family, whose most well-known members are citrus trees, and which also includes popular ornamental genera such as Choisya ternata (Mexican Orange Blossom) or Dictamnus albus, a surprising perennial that emits a plant essence capable of spontaneously igniting during hot weather!
The Orixa japonica is a native plant of Japan, South Korea, and northern China, where it grows in woods, thickets, and on cliffs up to an altitude of 1300 m. Known in private collections since at least 1784 and introduced to Western cultivation in the 1870s, this bush remains virtually unknown in our gardens. It is a dioecious plant, meaning that there are separate male and female plants, with flowers that have four sepals and four petals, plus four stamens in males and four carpels in females. This bush is known to grow quite slowly during the first 2 or 3 years, as it develops its root system, and then a bit faster afterwards. At maturity, it forms a dense mass, wider than tall, reaching approximately 2.50 m in height and 3 m in spread. The rather thin branches bear elliptical to ovate leaves, about 12 cm long and 6 cm wide. With a beautiful medium green colour, quite bright, and glabrous, they have the distinctive feature of having a very glossy upper surface, evoking the luxuriance of tropical foliage. The vegetation tolerates pruning very well, which is why the bush is frequently used for hedges, especially in Japan. Like most Rutaceae, the foliage is highly aromatic, but not everyone appreciates its scent.
Flowering occurs in April-May, in the form of short spreading clusters in male plants, while the flowers are solitary and long-stalked in females. With a greenish colour, the flowering has no ornamental interest. The fruits are a bit more interesting, formed by four compressed carpels that start off green and then turn brown. At maturity, the dehiscent fruit expels the seeds. However, it is necessary to remember that both a male and a female plant are needed for fertilisation... which is not really worth the effort.
Being deciduous, the foliage of Orixa falls in autumn, but before that, it turns a pale lemon yellow, not exceptional in itself, but it enhances red or orange autumnal colours.

A rare plant that is easy to cultivate and tolerates shade, even dense shade, especially in hot climates, Orixa japonica also withstands sea spray and can therefore be planted by the seaside. It is unaffected by diseases and insects, and while it appreciates humidity (in well-drained soil), a well-rooted plant can withstand drought. This plant, believed to have originated in the Pliocene (2.5 to 5.5 million years ago), has survived through the ages, which certainly explains its good adaptability. You can use it in a Japanese-style garden or to create a tropical-inspired scene, under the shade of a Magnolia macrophylla, with its enormous leaves that can reach 60 cm long. An Asimina triloba, or Paw-paw, would also be interesting to add an exotic touch. This medium-sized tree produces edible fruits with a mango-like appearance and a taste that is a cross between that of a tropical fruit and a banana. Also, not well-known among gardeners, the Viburnum odoratissimum is an evergreen bush with beautiful, fairly dark, shiny green leaves that turn red in autumn, like a deciduous plant, creating a pleasant contrast with the pale yellow of the Orixa. Additionally, it offers white spring flowering that is slightly fragrant and highly decorative.