Gardening: Sermons in stones

The classic Japanese garden relies on stone and water. Naila Green describes a centuries-old tradition of design

There may seem to be little or no connection between gardening and opera, but David Freeman's recent production of Madam Butterfly left me feeling horticulturally inspired. I was lured to see a performance by the promise of "an enchanting Japanese water garden" and further interested by the fact that this also transforms itself into a Zen Buddhist stone garden.

Water and stone feature strongly in Japanese gardens, with or without plants. They provide both contrast and balance, and the nature of each of them illustrates a concept essential to the design of the Japanese garden. Whereas stone represents the enduring and unchanging (the yo), water is its balance, and represents the constantly changing (the in). These opposites provide a balance.

The idea of in and yo is better known by its Chinese counterparts, yin and yang. It is central to oriental thought and art, and postulates that everything is balanced, and completed by, its opposite. Thus, night is balanced by day, strength is balanced by frailty and weakness, and masculinity is balanced by femininity.

In the garden, unity is achieved by the balancing of opposites. Solid forms are balanced with empty spaces, vertical forms with horizontal, movement with stillness, dark with light. Unlike people who work with traditional Western garden design, where symmetry is commonly used to achieve balance, Japanese gardeners use asymmetry with consummate skill and sensitivity.

Traditional Japanese water features are always naturalistic and irregular in shape. In and yo are achieved by the use of still water, in the form of reflective pools, and moving water in the form of winding streams. Stone has a special importance in the design of the Japanese garden, as shown by the fact that the earliest Japanese garden designers were ishitate- so, "priests who arrange stones".

In its various forms, stone can represent many different aspects of nature. Even water can be represented symbolically, in the kare-sansui or dry gardens, where lines raked on white sand represent the sea. In Shinto, the indigenous religion of Japan, spirits known as kami were thought to inhabit certain trees, rocks, mountains and waterfalls. This intimacy with nature is one of the strongest characteristics of the Japanese, and shows why rocks have been so important in their garden design.

In the garden, rocks form the basis on which the whole design depends. Most other elements in the garden change. Plants change as they grow, water changes as it moves, light and weather change, and even the people who use the garden change. The rocks, however, do not change.

The selection of each rock is crucial. Every stone is unique and its shape, texture and colour reveal its essence, mood and inner spirit. To aid selection, rocks were categorised into five main shapes. Tall, monolithic "body" stones would be used for dramatic effect, and usually placed at the back of a group. Low, vertical "soul" stones were placed towards the front of the group. Flat-topped horizontal "mind and body" stones were used to harmonise the rest and create a sense of tranquillity. "Arching" stones were placed to one side of the group and near the front, and the "reclining" stone, roughly the shape of a human figure lying on its side, was placed in the foreground.

Traditional Japanese style requires a search for stones whose natural shape suggests certain poetic ideas, or resembles nature in some way. Sometimes a stone would suggest the shape of an animal, or a natural feature such as a water cascade, which would be used in a dry garden. Stones are also used to build symbolic mountains and waterfalls, stream beds, lakes and islands, paths, stepping-stones and bridges. The shape of the stone can be used to suggest an island, promontory or mountain range. This type of representation should be sensitive, never over-elaborate or contrived. Stones with signs of erosion and weathering are preferred, and moss and lichen add patina, giving it added value, or sabi.

The arrangement is also considered in great detail. The Sakuteiki, an 11th-century treatise on gardening, and the world's earliest garden design handbook, advises that groups of two or more stones should be placed at important points in the garden. These can be symbolic stones. In general, stones should always be arranged in groups of odd numbers, unless you are making a group of two. If, for example, you have three stones to arrange, then you should make a group of two and one. Within the groups, stones must be of a different size but be in harmony with one another.

Whatever the arrangement or materials that are used, the traditional Japanese garden designer, the niwashi, aims to create a mood of tranquillity called yugen. Like an artist or musician, he does not imitate nature, but seeks to capture its mysterious and transcendental spirit.