The surroundings of a Japanese garden such as the buildings, tsukiyama (artificial hills), paths, terraces, and stone compositions determine its structure or framework. These gardens are constantly changing or are what would be called a living work of art, due to the fact that nature changes with the weather, climate, and seasons. Plants and trees are constantly pruned and sculpted to create a new experience for those experiencing it; hence, the phrase "A Japanese or Zen garden is never the same and never really finished."
A Zen Garden must be carefully maintained by those skilled in the art of training and pruning, or over time, it will lose the static effect the artists are trying to maintain.
All parts of the Zen Garden are symbolic of a greater feature in nature. The act of raking gravel into patterns recalls waves or rippling water, and helps the priests focus their concentration as they seek perfection in the lines of rocks. The patterns are not static though as they develop variations in patterns to create a greater experience. The stone arrangements represent mountains and other miniature elements portray natural water elements, rivers, waterfalls, and islands. Forest covered land is represented in the use of moss. The use of stone can also sometimes be used to symbolize boats, or even people as well.
The Sakuteiki "Creating a Garden", the most influential garden book for Japanese garden design outlines the art or act of "setting stones upright", ishi wo taten koto. When the Sakuteiki was written, the act of gardening was the placement of stones.
"Make sure that all the stones, right down to the front of the arrangement, are placed with their best sides showing. If a stone has an ugly-looking top you should place it so as to give prominence to its side. Even if this means it has to lean at a considerable angle, no one will notice. There should always be more horizontal than vertical stones. If there are 'running away' stones there must be 'chasing' stones. If there are 'leaning' stones, there must be 'supporting' stones."
"The influence of Zen on garden design was (probably) first described as such by Kuck in the early 20th century and disputed by Kuitert by the end of that century. What is not disputed is the fact that karesansui garden scenery was (and still is) inspired (or even based on) originally Chinese and later also Japanese, landscape paintings." -WikipediaInfluential Zen Gardens:
One of the most well known Japanese rock gardens is the garden at Ryoan-ji in northwest Kyoto, Japan. Another well know Zen garden is: Suizenji Koen in Kumamoto City, Kumamoto Prefecture Japan.
For more information on the art of the Japanese or Zen Gardens: The art of the Japanese GardenThe Art of the Japanese Garden by David Young, Michiko Young, Tan Hong Yew, or the most influential book on Zen Gardens: Sakuteiki: Visions of the Japanese Garden by Jiro Takei, and Marc P. Keane.