The principal behind Japanese gardens is the emphasis on form foliage and structures.
You can idealize a garden, even symbolize it, but you never can create something that nature itself cannot. For example you would never find a fountain in nature but you can see a waterfall. Another key in these gardens is to find balance or SUMI.
The designs are based on three principals, reduce scale,symbolization and borrowed view. Gardens in reduce scale represent scenes and places in small areas. Mountain views, and rivers are miniaturized using stones, sand and gravel.
TRADITIONAL JAPANASE GARDEN -
The traditional Japanese garden can be categorized into three types:
TSUKIYAMA- 
This garden recreate a reproduction of natural scenery with ponds,streams, hills,stones, bridges an trees. They are call the hill garden.
KARENSANSUI
This garden also calling the dry garden , reproduce natural land scape’s by using stones, sand and sometimes few patches representing mountains.
This gardens are influenced by ZEN BUDDHISM and are used for meditation. Appeared in (1333-1568 )
CHANIWA
Contrary to what one could expect from the name this type of garden wasn´t create for drink tea. It is around the tea house where Japanese have the ceremony tea. This garden is the passage to the tea house , represent the
connection between the outside world to the inner world of the tea-house. The purpose it´s to have a peaceful mind before starting the tea ceremony.
