From ancient times, Yamatsutsuji or Rhododendron kaempferi grew naturally in the area. In the Edo Era, different lords of Tatebayashi Castle planted Yamatsutsuji there and protected and nurtured them. In 1923, after going through some transitions, Gunma Prefecture became the owner of the area and turned it into a prefectural park. Many of the azaleas in the park are old and tall, some of which are more than 800 years old, and they are still growing today. When Yamatsutsuji are in full bloom, the landscape looks like a gigantic red carpet.
The soil of Kenritsu Tsutsujigaoka Park and its surrounding area contain black dirt, fine sand, and volcanic ash that is light and grainy, which is good for growing azaleas. Approximately 10,000 azaleas of more than 50 different kinds, including Yamatsutsuji, Kirishima-azaleas, and Ryukyu-azaleas grow in the park. These azaleas are at their best from the end of April to early May when the park turns red, purple, and white.
To the north, you can see the Jonuma pond that surrounded Tatebayashi Castle and protected it from enemy attacks in the feudal age. Japanese red pines also grow in the park. These pines and azaleas in full bloom are reflected on the surface of Jonuma pond. They are very beautiful and have been designated as a national scenic beauty.
There will be an admission fee when azaleas are in bloom (for about a month from early April). The Azalea Festival will be held during this period.