The Persian silk tree (Albizia Julibrissin â€˜Summer Chocolateâ€™) is a very exotic recent addition to the European flora. The Latin name is Albizia and it originated from Southern Asia. It is known as the sleeping tree in some countries because the feathery leaves gradually close at night and hang downwards as if the tree were asleep. The silk tree seems to stay asleep for some time in spring, too, as it does not develop new shoots until most other trees and bushes in the garden have come to life.
The silk tree captures the imagination, as is evident from the many names that it has been called, such as silk tree, sleeping tree, night sleeper, mimosa and Constantinople acacia, to name a few. The silk tree is not a mimosa, although it does belong to the same family. The variety â€˜Summer Chocolateâ€™ has magnificent brownish-red, tripinnate sickle-shaped leaves, which are a yellowish-green when they first emerge in early spring.
The Persian silk tree creates a tropical surprise when the silk tree starts to flower in July. The flowers are unusual as they have no petals, they produce a cluster of stamens and the pink flowers form a striking contrast with the brown leaves, giving the tree a tropical appearance. The tree will flower more abundantly in a warm summer. The leaves of the silk tree also close during wet weather. It is hardy and has a delightful fragrance which attracts butterflies.
The silk tree prefers a sheltered spot in the garden planted in a fertile well-drained soil. It is also drought tolerant. It is frost hardy and can withstand a minimum temperature of 12 to 15 degrees below freezing. Albizia is a fast growing tree that can be cut back to give a bushy effect in the border or it makes an excellent display planted in a pot for the patio. The tree flowers July-September and can grow up to 4 metres in height.
After flowering the tree develops long, flat pods containing the seeds for new trees. A warm greenhouse is needed in order for these seeds to germinate. Allow the pods to dry on the plant, collect the seeds by breaking open the pod and store until spring. The plants can be planted out in May when they have hardened off.