Sophora japonica

The Sophora japonica (now renamed Styphnolobium japonicum), better known as the Japanese Pagoda Tree, Pagoda Tree, or Japanese Sophora, is a majestic, vigorous, and easy-to-grow deciduous tree, more often planted in parks and along avenues than in gardens due to its potential for significant growth, depending on the growing conditions. With a beautiful wide and ample habit, it is adorned with elegant compound foliage of a bright green colour, providing a light and pleasant shade in summer. When its long panicles of small white-cream flowers appear, after more than twenty years of cultivation and during a hot summer, its fragrance fills the surrounding air.

The Sophora japonica belongs to the Fabaceae family, or legumes, and is a relative of wisteria, black locust, and laburnum, for example. It is native to central China and Korea. In nature, this tree naturally grows in arid plains. Recognised for its beautiful appearance, this sophora tree was often planted near pagodas, which earned it its name, Pagoda Tree. It was introduced in Europe in 1747 by Father d'Incarville. Not demanding in terms of soil, as long as it is well-drained, this tree can withstand summer drought once established. Young specimens are quite sensitive to severe frosts (-10/-12°C (14/10.4 °F at worst)), but adults can withstand freezing temperatures.

With rapid growth, the Japanese Sophora can reach a height of 20 m (65 ft 7 in) and a width of 15 m (49 ft 2 in) in fertile and cool soil, although it achieves more modest dimensions in Mediterranean regions for example. The tree generally develops a relatively short trunk and a wide rounded crown: it can be as wide as it is tall. The main branches are rather upright, while the young twigs are almost horizontal. Its deciduous leaves with a shiny dark green colour on the upper side measure 15 to 30 cm (5.9 to 11.8 in) in length, comprising seven to seventeen leaflets. Their undersides are pubescent, and they turn a beautiful bright yellow colour in autumn before falling. The flowering, which only appears after twenty years of cultivation, from late summer to autumn (late July to late September) depending on the climate, takes the form of beautiful 30 cm (11.8 in)-long panicles of small white-cream flowers. The flowers are nectar-rich and fragrant. The fruits that follow are pendulous pods reminiscent of pearl necklaces. The trunk of the Pagoda Tree becomes twisted with age and has longitudinally cracked bark. Its wood is brittle, and its root system is spreading and extensive: it is best to shelter it from strong winds that could uproot it. Like many plants in the Fabaceae family, the Sophora japonica has the ability to produce nodules on its roots that host specific bacteria, allowing it to thrive in poor soils by using the nitrogen present in the air.

The Japanese Sophora will express its full splendour in a large area, as a shade tree. It will become majestic if left unpruned and will make a beautiful focal point if placed in isolation on a lawn. If you have space, combine it with other summer-flowering trees (Albizia Summer Chocolate, Eudia danielii, etc.) or autumn foliage.

The Pagoda Tree will reach its full potential during hot summers. It is a plant used in phytotherapy, with all parts having purgative properties. In the past, the flowers, leaf buds, and leaves were used to obtain yellow dye, and the fragrant flowers were used in cosmetics.