The tree wisteria (Bolusanthus speciosus) offers a spectacular vision in spring. Picture: Kay Montgomery

Johannesburg - National Arbor Week (September 1 to 7) is a time we are encouraged to promote the planting and maintenance of indigenous trees.

Trees provide shade in summer and shelter for birds.

Studies have also shown that over a period of about 15 years, approximately 500kg of carbon is “stored” per tree.

SA’s 1973 Green Heritage Campaign suggested a National Tree of the Year celebration and by 1982, the concept was launched by the former Department of Forestry. In 1996, Arbor Day was extended to a week.

“Our forests, our future” is the 2012 theme of this year’s celebrations and three indigenous trees are under the spotlight as National Trees of the Year. Only one of these three trees can possibly survive in a Joburg garden, the water-loving indigenous waterberry (Syzygium cordatum). An evergreen 6-15m tall tree, it only does well in a full sun near a stream, near a pond or in a damp, well-irrigated garden. Scented feathery cream flowers bloom from spring to winter and attract bees and other insects that attract birds. The flowers are followed by purple fruit that is eaten by animals.

The others are a mangrove species (black mangrove, Bruguiera gymnorrhiza) from the subtropical KwaZulu-Natal coast and a frost-tender forest tree (red beech, Protorhus longifolia) from the Transkei coastal belt.

If your garden is very small, it might be best to choose a deciduous tree that will lose its leaves in winter, thus allowing your home to receive much-needed winter sun for warmth in the colder months.

Conversely, a small evergreen tree might be ideal for providing privacy for your garden from neighbouring upstairs’ windows. Prune the lower branches of evergreen trees as they grow to allow more light into the garden or house.

Trees for small gardens

Here are a host of indigenous trees that are ideally suited to small Gauteng gardens and can be planted this weekend:

* September bells (Rothmannia globosa) is an attractive spring-flowering tree with sweetly scented, creamy-white, bell-shaped clusters of flowers that are produced each September. September Bells will grow into a rounded shrub, or can be encouraged to grow as a small tree.

* Tree wisteria (Bolusanthus speciosus). This deciduous tree grows to a height and spread of 7x4m. It has a slender, erect shape with an attractive bark and bears masses of lilac-blue flowers.

* Pompon tree (Dais cotinifolia). A fast-growing evergreen tree with a height and spread of 5x3m. It bears pretty pink flowers in summer and yellow foliage in autumn.

* Karee (Searsia lancea previously known as Rhus lancea). A very hardy evergreen tree with an interesting trunk and branch growth patterns. It has a height and spread of 7x5m with long, narrow, weeping leaves.

* White karee (Searsia pendulina previously Rhus pendulina). A water wise, evergreen tree with pretty, willow-like foliage. Its height and spread is 7mx5m. It bears light green leaves and sprays of tiny greenish-yellow flowers.

* Lavender tree (Heteropyxis natalensis). A deciduous tree that grows up to 6m high and 5m wide. It has attractive bark that starts off smooth and white, and becomes grey and flaky with age, revealing patches of orange-brown bark beneath. New spring growth is tinged red, becoming glossy green in summer before turning autumn shades.

* White gardenia (Gardenia thunbergia). This evergreen tree grows to 2.5m high and 1.5m wide. It bears highly fragrant white flowers in midsummer. The foliage is shiny and crinkled.

* Forest bushwillow (Combretum kraussii). A deciduous tree with a height and spread of 7x4m. It bears beautiful autumn foliage and its dense canopy makes it a great shade tree.

* Wild pear (Dombeya rotundifolia). A waterwise deciduous tree up to 6m high. Bears clusters of white flowers in spring. - Saturday Star