The origin of Zen rock garden is from China

Quick answer：

Zen rock gardens, known as 'Karesansui' in Japanese, indeed have their roots in Chinese landscape gardening. They were brought to Japan during the 14th century by the Zen monks, who adapted the concept to fit the Japanese aesthetic. These gardens are characterized by their minimalist design, using rocks, sand, and sometimes moss to represent natural landscapes like mountains and rivers, emphasizing the essence of nature without its distractions. The influence of these gardens can be traced back to the Chinese tradition of rock gardens, particularly those found in the Song Dynasty (960-1279 AD).