Albizzia julibrissin Ernest Wilson

The 'Ernest Wilson' Albizia julibrissin is a cultivar discovered in 1918 by an American collector of the same name in the garden of a hotel in Seoul, in central Korea, which is colder than coastal areas. The seeds collected and planted upon his return to cold New England have given rise to a tree that is still thriving a century later. This cultivar is therefore considered the most cold-resistant and exceptionally long-lived. It produces bright white and pink flowers, a particularly vibrant colour against its tender green, finely cut foliage. It should be planted in full sun, in well-drained soil and protected from cold winds.

The Albizia julibrissin is a deciduous small tree of the Fabaceae family, with a distribution range that extends from Iran to eastern China. 'Ernest Wilson' usually reaches a height of 2.5 to 3 m (8 to 10ft) in our climates, but if the growing conditions suit it, it can reach a height of 6 m (20ft) with a similar spread. It develops a spreading canopy with a diameter equal to or slightly greater than its height. This small tree blooms in July-August, in the form of feathery and silky flower heads that have earned it the name of silk tree. They are composed of long stamens in a deep pink colour, white at the base, surpassing the rudimentary corollas grouped in heads. The fragrance of the flowers is most noticeable up close, powdery and sweet. The flowering gives way to a fruit, a flat pod, 8 to 20 cm (3 to 8in) long, initially green and then brown, containing 5 to 15 fairly large oval seeds, which germinate easily. The deciduous leaves, light green, are alternate and very large, measuring from 15 to 40 cm (6 to 16in). They are divided into large leaflets, which are further subdivided into small leaflets. The bark is thin, gray-green and then grey, almost smooth, with whitish lenticels. Finally, and this is a characteristic of plants in the fabaceae family, the roots form nodules capable of fixing atmospheric nitrogen, through specific bacteria present in these organs. The taproot system of this small tree does not tolerate transplantation well. The lifespan of the Albizia is variable, and in our climates it usually reaches around thirty years.

Perfect for small gardens, the 'Ernest Wilson' silk tree charms with its graceful silhouette and light foliage adorned with exotic flowering in summer. It can be planted as a standalone tree, where one wishes to enjoy its light shade, near a terrace for example. It brings a pleasantly exotic touch to the garden. Its hardiness is ensured by planting it in well-drained soil, in full sun, protected from prevailing winds and cold drafts.