Styrax shiraiana

Styrax shiraiana, introduced to the USA in 1915 and imported to England 30 years later, still struggles to find its way into European botanical gardens, and even more so into the hands of rare plant enthusiasts. Endemic to Japan, this tall deciduous shrub or small tree with purple-brown bark is entirely covered in star-shaped hairs, it bears broad dentate leaves reminiscent of witch hazel and offers beautiful white flowering in May. To give it the best chance, provide it with moist but well-drained soil, preferably with an acidic tendency. To fully enjoy its presence, give it a prime spot in the garden.

Styrax shiraiana belongs to the Styracaceae, a botanical family that includes several trees and bushes with aromatic resin, most of which are native to Asia. It is a large ornamental bush that thrives in partial shade and prefers a fresh, humus-rich, non-chalky soil, and can be found at altitude on the Japanese island of Honshu.

With rather slow growth, this styrax has an elegant habit. At maturity, it will reach an average height of 5.50m (18ft) with a width of 3m, depending on the growing conditions. Its bark is grey-brown to purple-brown in colour, and is covered in numerous star-shaped hairs, just like the entire plant. The deciduous foliage falls in autumn and reappears in spring. It consists of entire leaves, arranged alternately, measuring 5 to 9 cm (2 to 4in) in length, with a triangular shape and widened tips, as well as small teeth. Their colour is a medium green, turning yellow in autumn. Flowering occurs in May. It takes the form of clusters or racemes that appear at the terminal ends of the branches. Each raceme measures 3 to 6 cm (1 to 2in) in length and contains 8 to 10 pendulous white flowers. The funnel-shaped corolla is formed by 5 petals. After pollination by insects, the flowers give way to ovoid fruits, 1 to 2 cm (1in) long, ripening in November. Each fruit contains only one seed. The hardiness of this Styrax is yet to be determined, but based on its origins it should withstand temperatures below -12°C (10.4°F).

To acclimate this Styrax give it a few hours of sunlight, but avoid the hottest hours of the day. It thrives in humus-rich, acidic, fresh, and light soils, a type that hydrangeas love. Plant it in isolation, near a pathway or not far from the house, to fully enjoy its rare charm. It can be paired with shrubs with dark or, conversely, golden foliage, such as the superb ones from the Physocarpus family (All Black, Dart's Gold). Japanese garden enthusiasts might like to combine it with its cousin, Styrax japonica, and Japanese maples.