Cross the crosswalk at Hirakawa Gate intersection in front of Palaceside Building and you reach the East Gardens of the Imperial Palace — an urban oasis surrounded by deep green forest. In the "Ninomaru Garden" within, trees representing every prefecture are planted＝photo. Hokkaido's Ezo spruce, Aomori's hiba, Iwate's Nambu red pine, Miyagi's keyaki, Akita's Akita cedar, Yamagata's cherry, Fukushima's keyaki... Tokyo's is ginkgo; Okinawa's is Ryukyu pine.
Prefectural trees were apparently designated nationwide in fiscal 1966, aligned with the "Green Nippon National Campaign" proposed by The Mainichi Newspapers.
The Imperial Family and forests have always been deeply linked. Each spring the Emperor and Empress visit a prefecture and attend the National Tree-Planting Festival, always planting and sowing seeds by hand, watching the trees grow. For resource-poor Japan, forests are a major natural asset and vital to the environment — a fact the Imperial Family demonstrates in practice.
The first festival was in 1950 (Showa 25), but it traces back to the prewar "Arbor Day (airinbi) tree-planting movement." In 1895 (Meiji 28), American educator Northrop introduced his country's "Arbor Day" to Japan. The government then set November 3, Tencho-setsu (Emperor Meiji's birthday), as "School Planting Day" and ordered schools nationwide to create school forests. In 1898 (Meiji 31), forestry authority Dr. Honda Seiroku proposed April 3, Jinmu Festival, as planting day. Interrupted by World War II and postwar chaos, the festival was revived in 1950 — to rebuild scorched Japan into a green nation again.
Since 1977 (Showa 52), the National Tree-Care Festival has been held to prune and maintain trees planted in earlier years. The Crown Prince attends. Both festivals draw large numbers of local children who learn the value of greenery.
The Mainichi Newspapers also maintains an in-house Water and Green Earth Environment Headquarters, leading media in environmental conservation through tree planting, Mount Fuji cleanup campaigns, and more.