The genus Leptospermum belongs to the myrtle family Myrtaceae. About 80 evergreen shrubs and small trees make up the genus. Mostly the species are endemic to Australia with one being from New Zealand and 2 from Southeast Asia. The small narrow leaves are often scented and the small, star-like flowers have a wide cup for nectar surrounded by 5 petals. White, pink and red of all shades and in great profusion make up the colours for what is commonly known as tea-trees (sometimes ti-trees). It is believed the leaves of some species were used by early settlers as a substitute for tea.
Leptospermum leuhmannii is a tall shrub native to subtropical Queensland where it is found on rocky outcrops. The light brown bark peels each year exposing striking bronze, cream or green new bark. This attractive bark, together with shiny green leaves and masses of clusters of small white flowers makes this a very stunning plant.
Another species with white flowers but silky, pale grey-green leaves is Leptospermum grandiflorum which can grow to 5 metres. This spreading shrub is endemic to Tasmania and is ideal as a shelter or screening plant.
Leptospermum squarrosum is also known as the Peach-flowered Tea-tree. It is native to poor sandstone soils around Sydney, New South Wales. It is an erect, open shrub, bushy with narrow, prickly, dark green leaves. Profuse white to deep pink flowers appear along the older branches mainly from February to April. It is hardy and adaptable to a range of conditions but does like good drainage. It is frost tolerant.
Leptospermum laevigatum or Coastal Tea-tree is widespread in eastern coastal areas of Australia. It is a bushy shrub or small tree, and often has a twisted, gnarled trunk. The small, grey-green leaves have rounded tips. The conspicuous white flowers appear mainly from September to December. It is fast growing and is an excellent choice for exposed coastal situations. Under ideal conditions, it may become invasive. This has been the case in South Africa where it is considered a weed. Birds love this species with many species happy to nest in the branches. The papery bark provides good nesting material.
The leptospermum makes a graceful screening plant. Most are best suited to well-drained soil and full sun although a few species will tolerate wet conditions and almost full shade. They should be pruned regularly after flowering to retain their shape and bushiness. Slow-release fertilisers applied in spring will benefit the plants. Generally they will only tolerate an occasional light frost. Cultivars need to be propagated from cuttings if they are to retain their particular characteristics.