Family: Mimosaceae
Common Name: Silk Tree

Native to tropical and subtropical areas of Asia, Africa and Australia, this genus comprises over 150 species which are closely related to the wattles. Some species are grown for their timber, especially in Southeast Asia. The ferny, wattle-like leaves fold up at night and the clustered bundles of stamens have a silky appearance. Albizias are grown for the beauty of their flowers and foliage. In areas prone to frost, tender species are grown under glass. Outdoors they are suitable for shade and for quick-growing shelter. They are sometimes used as shade trees in tea and coffee plantations. They also make attractive street trees as they can withstand pruning on a regular basis.

Species

A. julibrissin, pink silk tree, zone 7, is native to central Asia. A hardy, deciduous tree, it reaches 6-9 m (20-30 ft) in height. It has deep green fern-like foliage and rounded brushes of translucent pink stamens, which look like silky tassels. Its appearance changes at night as the leaves fold up.

A. lebbeck, Siris tree, zone 9, from tropical parts of Asia, is an excellent deciduous shade and street tree. It grows 12-14 m (40-45 ft) tall. It is sensitive to frost but can withstand heat and drought. It has pretty sprays of creamy pink flowers.

A. lophantha, cape or crested wattle, zone 9, is native to Western Australia, and now naturalized on the east coast of Australia. It is valued for its rapid growth, its salt tolerance and its suitability for seaside plantings. The dense cylindrical spikes of greenish yellow flowers have a strange smell, so planting albizias close to the house should be avoided.

Cultivation

Tender species can be grown in pots of well-drained soil-based compost in a cool greenhouse or conservatory. Outdoors, these trees enjoy a light, well-drained soil. The pea-shaped seed pods provide abundant seeds for ease of propagation. Seed sown in spring can produce plants of 2.5 m (8 ft) by winter.

Climate

Depends on species; some thrive in zone 7, others in zone 9.