Garden designers around the country could take a few ideas from the Sendai Yasoen (Wild Flower Garden) by using more native plants in their own designs.
Indeed, Japan has wonderful native wild plants, yet strange to say, some Japanese plants are more popular in the British Isles or the cooler parts of North America than they are in their homeland. Sendai Yasoen's 9.1 hectares are located on the side of a hill, about 100 meters above sea level, in the south part of the city on land originally belonging to nearby Dainenji. The annual precipitation is 1,200 mm, including both rain and snow, and the annual average temperature is just 11.9 C.
This is the northern limit of the warm-temperate region (dan'on-tai). Evergreen trees and shrubs from the laurel forest (shoyo-jurin) can be found growing in this garden and the surrounding immediate area. The camphor tree (kusu-no-ki, Cinnamomum camphora) and the Japanese camellia (tsubaki, Camellia japonica) grow successfully here.
The warm-temperate region meets the temperate region (on-tai) at Sendai, which lies close to the 38th parallel north latitude. The temperate climatic zone starts at about 1,000-1,500 meters above sea level in Kyushu and southern Shikoku, and gradually decreases in altitude in the northern Kanto before coming down to sea level in the Sendai area. This temperate zone then continues along the coast to the southern part of Hokkaido.
The intermediate forest zone between warm-temperate and temperate is dominated by trees such as the deciduous konara oak (Quercus serrata), Japanese chestnut (kuri, Castanea crenata) and the Japanese red pine (akamatsu, Pinus densiflora). The giant bamboo (moso-chiku, Phyllostachys edulis) and the timber bamboo (madake, P. bambusoides) also have their northern limits around the 38th parallel. The Yasoen collection has 350 species of trees and shrubs and 800 of wildflowers; most are native to Japan, though some originate in China. Close to the main entrance is a small but interesting rock garden, where the relatively hard-to-cultivate komakusa (Dicentra peregrina) can be found growing in full exposure to the sun in a bed of scree (sandy and gravelly soil).
This delicate-looking plant is one of the best loved of all the Japanese alpine plants. In the wild it grows mainly on the screes of volcanic mountains in Honshu and Hokkaido. In the Yasoen the little red flowers open in mid-May.
The lower end of the garden features wetland plants, and between these two areas there is a deep mountain area. On my visit to the Yasoen I turned left just inside the main entrance and walked past the library and office down to a large lawn area which has borders of wild flowers. Among them was ominaeshi (Patrinia scabiosaefolia), an herbaceous perennial growing 60-100 cm high, whose stems are crowned with many tiny yellow flowers. The normal flowering time is August through October.
Growing right next to the ominaeshi was fujibakama (Eupatorium fortunei), another herbaceous perennial which came to Japan from China during the Nara Period (710-794). Its pinkish-white flowers are borne in a dense corymb at the top of stems 100-150 cm tall. Fujibakama and ominaeshi are two of the seven flowers of autumn. The other five, Japanese arrowroot (kuzu, Pueraria lobata), balloon flower (kikyo, Platycodon grandiflorum), large pink (kawara-nadeshiko, Dianthus superbus var. longicalycinus), eulalia grass (susuki, Miscanthus sinensis) and bush clover (hagi, Lespedeza thunbergii) can be seen in this garden as well.
Hagi, in fact, is the flower of Sendai. In the garden there is a well-made hagi "tunnel" that is fashioned by training young branches of hagi over a frame made from thin bamboo. During the winter months the old branches are cut back to ground level. When spring comes around new branches emerge from the base. The sloping lawn in front of the ominaeshi is covered with chidome-kusa (Hydrocotyle sibthorpioides), a perennial plant whose leaves are supposed to be able to stanch the flow of blood, hence the name. So far I have never had cause to test it, though.
On one red pine a climbing hydrangea (tsuru-ajisai, Hydrangea petiolaris) is growing way up along the trunk. In Europe this hydrangea is popular for growing on north-facing walls or semi-shaded areas of the garden. This climber is also very happy growing in full sun. The stems attach themselves to trees or buildings by means of aerial roots; their white flat-topped clusters of flowers are produced in June and July. The outer part of the flower is composed of showy infertile flowers with three to five petals, while in the center of the flower are tiny fertile flowers, each containing 15-22 stamens. Climbing hydrangea prefer well-drained soil enriched with leaf mold. Young plants will need to be tied to a tree or special frame until they can support themselves by their own aerial roots. The garden also has a good collection of bush hydrangeas, including amacha (Hydrangea macrophylla var. thunbergii), cultivated for the sweet-tasting tea that is made from its leaves. H. macrophylla var. oamacha is another variety which is also grown for making a tea. (Hydrangea tea is normally drunk to celebrate the birthday of Buddha.)
The flowers of both are of the lacecap or gaku-ajisai type, and not very showy; amacha has white flowers whereas oamacha has light pink fertile flowers and clear pink sterile florets. This many-branched shrub grows to 70-100 cm tall.
One of my favorite Japanese trees can be seen growing in the "deep mountain" area of the garden: the mizuki or dogwood (Cornus controversa). This beautiful tree with its almost horizontal branches is common in the mountains all over Japan. The flowers are arranged in corymbs, each 10-15 cm wide and open in May or June. Its small fruits are black in color and ripen in October-November; it also offers good autumn color, ranging from yellow in shaded areas to purple-crimson in sunny positions. Wood from this tree is used to make personal seals, chopsticks, geta, wooden dolls and even for building material. Occasionally dogwood is planted as a street tree.
The Ainu name for the tree is utukanni, and it is used to make requests to their god. This "deep mountain" area was made around a steep, wooded section of the garden. On the pathway up through the trees a Japanese garden element is very cleverly incorporated into the woodland garden design: Water from a tiny stream is used to fill a water basin or chozubachi, also sometimes called a tsukubai. Buried in the ground beneath the small stones in front of the water basin is a suikinkutsu (water harp), an inverted pot placed into the ground with a hole at the top so as to let droplets of water enter and create pleasant sounds as they splash. The jar used for this is Karatsu pottery, and is 87 cm high. I once had the great pleasure of putting suikinkutsu into a garden in Osaka.
The park office is close to the main entrance, with the well-stocked library next door. In front of the library is a specimen of Akita-buki (Petasites japonicus var. giganteus). Native to moist woodlands of northern Honshu and Hokkaido, this giant herbaceous perennial has leaves up to 150 cm wide and leaf stalks 2 meters long. This specimen is not as large as a wild plant, but still impressive.