Tree of the week: Bolusanthus speciosus – Tree wisteria – Vanwykshout

Bolusanthus speciosus is a protected tree of South Africa whose blooms resemble those of Jacaranda. Although it is slow growing and delicate looking, this tree can reach a mature height of 6 to 12m when growing conditions are favourable. It is widely distributed in wooded grasslands of the Northern Province, Mpumalanga, Swaziland and KwaZulu-Natal. This tree has been reported to be a good indicator of underground water.

Shiny leaves of the Tree wisteria are droopy and are located at the ends of branches. Each leaf has about three to seven leaflets and a terminal one. B. speciosus has a short flowering period [from August to January].  Although classified as deciduous, the tree is only without leaves for a short time in early spring. The violet to pale blue flowers emerge on the tree before new leaves, these flowers may almost cover the tree. After flowering, narrow, thin non-splitting brown pods are produced. These hang on the tree in clusters. On young branches, the bark is normally smooth and grey becoming deeply grooved as the branches mature. The stems are usually straight even when the tree is multi-stemmed.

Bolusanthus speciosus makes a good specimen tree for small to medium sized gardens. It also makes a very neat street tree with a stunning display especially when in flower. The root system of this tree is not invasive. It is also a popular tree for bonsai. B.speciosus tolerates moderate frost, however young plants need protection during the first few seasons.