Significance Following the inauguration of China National Botanical Garden and South China National Botanical Garden in 2022, people become increasingly interested in the founding history of public gardens and botanical gardens in modern China. Professor Sun Xiaoxiang (1921–2018) is a pioneer in Chinese modern landscape architecture, and the primary founder of the discipline of landscape planning and design in China. As an educator, a landscape architect, a florist, a painter, an architect and a landscape planner, Professor Sun has planned and designed many internationally influential large public gardens and botanical gardens in China throughout his prolific life, including China National Botanical Garden and South China National Botanical Garden. This research systematically summarizes Professor Sun's theory, practice, career, representative works and historical contributions in the field of landscape architecture, to provide a reference for academic researches on the formation and development of public gardens and botanical gardens in modern China, in all respects. By studying archives spanning over 70 years of Professor Sun Xiaoxiang's academic documents on landscape architecture, this research creates a timeline of his career and works. Through the lens of history, the research formulates a pattern to demonstrate that many of Professor Sun's groundbreaking ideals are often ahead of their time, only to be proven visionary over time or decades later. By methodically following Professor Sun's professional footsteps and analyzing the creation, evolution and historical background of his works with a focus on the united formation thereof, the research renders a microcosm of the 70-year founding and development history of both public gardens and botanical gardens in China, engraved with Professor Sun's immortal contributions every step along the way.

Progress Professor Sun Xiaoxiang graduated from Zhejiang Univerisity in 1946 with a bachelor of agriculture in landscape design. He once taught at Zhejiang University, China Agriculture University and Beijing Forestry University in China, and lectured at 30 prestigious foreign universities, including Harvard University in the US and Curtin University in Australia. The classic textbook Garden Art and Landscape Design he authored has been widely used by all universities in China in the field of landscape architecture for over 30 years and has influenced scholars and students for several generations. In the 1950s and 1960s, he completed the Master Plan of West Lake Area, planned and designed his first and most famous design works, Huagangguanyu Park (Viewing Fish at Flower Harbor, one of the ten scenic spots of Hangzhou West Lake), and the Hangzhou Botanical Garden, including the plant taxonomy system area therein. He then planned and designed the Botanical Garden of Beijing Forestry University, the Beijing Botanical Garden (predecessor of the China National Botanical Garden inaugurated in 2022), the South China Botanical Garden of the Chinese Academy of Sciences (predecessor of the South China National Botanical Garden inaugurated in 2022), he also successively planned and designed the Hainan Botanical Garden and Xiamen Botanical Garden. In the early 1980s, he reselected the site and completed the master plan of Shenzhen Fairy Lake Botanical Garden, famous for the beautiful man-made "Fairy Lake", which he artistically named and designed based on Chinese folklore. In 2006, he completed the new master plan for Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences (XTBG), the largest botanical garden in China with an area of 1, 125 hm², including 250 hm² of well-preserved primary tropical rainforest. The excellent preservation of over 13, 000 species of plants in its 38 living collections has enhanced its reputation for being one of the most diverse botanical gardens for outdoor plants in the world. The "Hundred Flowers Garden" designed by Professor Sun, which consists of 33 gardens within, is the main scenery area of XTBG. XTBG was awarded "National 5A Travel Scenic Spot" in 2011, and has since gained ever-growing attention worldwide. In 2013, Professor Sun completed the master planning of Yunnan Jingdong Subtropical Botanical Garden, which was a challenging undertaking entailing the highest skillset and extensive experience due to its mountainous site and the relative height difference of up to 700 meters in some places. Professor Sun defined the essence of the heritage of Chinese classical garden, as the art of the ideal landscape school of scholar's garden, which consists of "Three States": The Natural State (natural in landscaping), the Picturesque State (picturesque in composition) and the Ideal State (poetic in feelings of the heart). He established Chinese modern landscape architecture education model, known as "walking with 5 legs" (one leg each as a painter, an ecologist, a horticulturist, an architect and a poet). For decades, his theory and education model have been internationally influential.

Conclusions and Prospects Professor Sun Xiaoxiang's theory originates from his lifelong practice, his practice is based on proven theories, and his landscape architecture works are the results of the continuous combination, refinement and perfection of his theory and practice. His ideals and works have forged the path, led the direction, laid the foundation and set an example for creating world-class public gardens and botanical gardens that combine science and art, east and west, contemporary and classicality, nature and culture, and abstract and reality seamlessly. With his works extending all over China in different climatic zones, Professor Sun Xiaoxiang has made significant contributions to species preservation and ex situ conservation for plant diversity, sustainable development of human living environment, and exertion of the ecological, social, aesthetic and economic effects of public gardens and botanical gardens. In 2014, Professor Sun was awarded the "Sir Geoffrey Jellicoe Award", the highest honor that the International Federation of Landscape Architects (IFLA) can bestow upon a landscape architect, in recognition of the unique and profound impact of his lifetime achievements and contributions in promoting the development of landscape architecture for the benefit of mankind, society and the environment, making him the first winner of the award in Asia. His achievements and contributions have been documented in the book of IFLA Book 2010–2014, and his legacy will be carried forward and continue to inspire others well into the future.