The Vegetation of Keio Yokohama Elementary School

2023/11/30

At Keio Yokohama Elementary School, out of a total site area of 37,995 m², approximately 38% (14,542 m²) is utilized for biotopes, woodlands, vegetable gardens, and gardens, while approximately 36% (13,716 m²) is used as a natural grass field. Approximately 20,000 trees and flowering plants of 196 species are planted on the grounds. Starting with the Thunberg spirea (*yukiyanagi*), which heralds the arrival of spring, trees and fruit trees that bear flowers and fruit can be observed on campus throughout the year. These plantings were conceived by the Keio Yokohama Elementary School Preparatory Office and were selected based on themes such as (1) allowing one to feel the changing of the seasons, (2) serving as learning material throughout the year, and (3) bearing fruit in succession with the seasons. For example, from the Japanese-style room (Bountei), built for learning the tea ceremony and flower arrangement, one can see Enshu mallow hibiscus (*Enshumukuge*), camellia (*Seiobo*), and pearl-bush (*Rikyu-bai*), which are used as tea flowers (*chabana*).

Among the selected trees are many edible fruit trees, such as loquat, bitter summer orange (*natsumikan*), lemon, mulberry, bayberry, and pomegranate. Because Keio Yokohama Elementary School emphasizes concrete observation and hands-on experience, an environment has been created where students can freely interact with the plants. As a result, many of the edible fruits are harvested within the students' reach or within a range accessible through creative efforts like getting on someone's shoulders. Depending on the season, the fruit on the lower parts of the trees is picked completely clean.

Even trees whose fruit is difficult for humans to eat play a role in attracting a wide variety of insects. In "Keio Yokohama Elementary School 10th Anniversary Commemorative Publication," produced to commemorate the school's 10th anniversary, first Head of School Keita Yamauchi contributed a comment stating that "the trees around the biotope were selected while imagining children chasing butterflies." The camphor tree, which Keio Yokohama Elementary School considers its symbol tree, nurtures the common bluebottle butterfly (*Aosujiageha*) with its vibrant wings, while the Japanese prickly ash (*Karasuzansho*), with its sharp thorns, invites the spangle (*Kuroageha*) and Chinese peacock (*Karasuageha*) butterflies to Keio Yokohama Elementary School. The Japanese prickly ash, which also attracts the Japanese bush warbler (*uguisu*), seems to be loved by butterflies and birds, even while being considered useless to humans.

Finally, I will describe the changes in vegetation since the school's opening. While ginkgo, *Ryobu* (Clethra barbinervis), and trifoliate orange (*Karatachi*) trees have disappeared, other trees have grown naturally, perhaps due to seed dispersal by wild birds or by students and faculty. An example is a persimmon tree near the biotope. There is a proverb, "Peaches and chestnuts in three years, persimmons in eight," and true to this, a persimmon tree, whose existence was likely unnoticed by anyone until it bore fruit, suddenly appeared in 2022. Although it is a wild persimmon, its taste is somewhat inferior compared to the pre-existing persimmon tree in the carefully managed vegetable garden. Furthermore, trees such as the Japanese elm (*Akinire*) have grown from seedlings (naturally sprouted from seeds), and a gradual ecological succession of vegetation has been observed. When you visit Keio Yokohama Elementary School, I hope you will also take notice of the flowers, fruit trees, and the insects that gather around them.

(Yohei Naya, Keio Yokohama Elementary School)