Rock gardens can be big or small, ornate or simple, but no matter how they are built, they are a source of peace and contain artistic flair. In Japan, gardens are considered an important art form; the influence of Zen Buddhism has shaped the culture of rock gardens even to Western shores. The most important aspect of rock gardens are the style and type of rock used to create them.
River rock is a slick, white/gray stone that comes in a variety of sizes from crushed stone that resembles a crumbly dust, to 2-inch round rocks. It works well for borders, paths and ground cover.
Slate is a white/gray stone that comes in flakes, or plates. It is a fragile rock that breaks easily so it can be molded to fit into desired spots. It stacks well and is strong inside a stack.
The best rocks for a rock garden are subdued in color. They should not be so flashy as to take away from the overall visual aspect or interrupt the peaceful nature of the garden. White, gray, red or clay rocks blend in well with both vegetation gardens and all stone gardens.
In Zen or Japanese gardens the stones also have a symbolism attached. The correct type of stone is vital to the success of the garden. There are five basic stone shape symbolisms. The first is taido. It stands for the element wood, and is vertical and tall, giving the impression of trees. These stones are also known by some as body stones. They are placed at the back of groups. The second is reisho. It stands for the element metal and is a vertical, low standing stone. It is solid and gives the impression of strength and firmness. It is also known as the soul stone and is grouped with the tall, body stones. The third stone is shintai. It stands for water. It is flat and horizontal. It is also known as the mind and body stone and is used to harmonize rock groups. The fifth is kikyaku. It represents earth. It is a reclining stone also called the root, or prostrate stone. It is placed in the foreground of groupings and implies power and tranquility.