Apart from their individual beauty over the seasons, which in the case of deciduous trees can range from the unfurling of new buds to a spectacular autumn display, they may be used to define a space for a particular purpose, provide a screen, act as a windbreak or a sunshade and offer a home for birds and other fauna.

Colourful bark, flowers or fruits are not only a bonus but often provide welcome contrast of texture to other plantings. Leaf fall from any tree enriches the soil with nutrients and humus which results from the breakdown of cellular tissue.

It is difficult to imagine now that the nation’s capital city begin life on a treeless sheep run but even while the first buildings were being constructed the planting of trees was considered part of the eventual design. The rich autumn colours of millions of exotic trees currently add to the stunning views from any of the city’s major lookouts. Plentiful summer water, dry days and cool autumn nights will bring out their colourful best.

Pistacia chinensis, a quick to grow shade tree 9m x 6m, is one of a genus of small drought hardy ornamental and fruiting trees that originated in the Mediterranean and Asia. Both male and female plants carry brilliant orange and red autumn foliage, though the females have additional pinkish red berries.

Nyssa sylvatica and Parrotia persica two small highly decorative trees that deserve to be more widely grown. Parrotia or witch hazel, seldom grows more the 8-9m in height. Pruning is neither necessary nor desirable which gives full reign to colours of yellow, orange and sometimes bright red. Smooth grey winter bark turns black when wet, while early red flowers appear on bare branches. Nyssa or the sour gum, is one for permanently damp spots.

No autumn garden should be without what many consider to be three of the most important smaller trees: maples, dogwoods and crabapples – any one of which deserves its own column.

Acer palmatum, the Japanese maple is well suited to sheltered courtyards for the delicate foliage can be scorched by hot summer wind.

Leaf colour can range from the palest peach, fresh lime green and emerald of spring to the yellows, orange and clarets of autumn.