Arisugawa Memorial Park has an area of 3.6 hectares and is the largest park in Tokyo’s Minato Ward. The collection of tall mature trees gives the park a pleasing woodland effect.

Arisugawa, near Hiroo Station, is in the heart of Tokyo’s embassy land and there is a very international feeling in the garden. Children and parents from many nations can be seen relaxing and playing in this park. Office workers come here during their lunch breaks, or use the park as a pleasant shortcut.

During the Tokugawa Period this area belonged to the Nanbu family, lords of what is now Morioka in the Tohoku region, who built their Edo residence here.

In compliance with the strict Tokugawa law of sankin-kotai, all daimyo were compelled to reside in their Edo residence every other year, and keep their families there permanently. This law, intended merely to keep a close eye on even close Tokugawa allies, made Edo a great cultural center, and bequeathed present-day Tokyo, among other things, a greater number of historical parks and gardens than any other city in Japan.

Each of these historical gardens in Tokyo has its own special features, be it the Chinese-influenced design of Koishikawa Korakuen or the glorified salt marsh of Hamarikyu, originally a hawking and duck-hunting preserve for Tokugawa Tsunashige, father of the sixth shogun, Ienobu.

One of the beauties of Arisugawa park is that it clearly retains the natural geographical contours of the old Arisugawa River. Long ago this short tributary river would have connected to the Shibuya River. Alas, the Arisugawa is no longer visible.

In the lower section of the park close to the main entrance there is a nice pond. At one time it was fed by a well; now a recycle pumping system is used. Nevertheless this pond with its two nakajima (islands) has its own special appeal.

In many Japanese gardens with ponds you may notice a small “island” or two — sometimes no more than a couple of rocks sticking their heads above the surface of the water. The islands symbolize the mythical Horai, an island where immortals live, which has its origins way back in China’s Han Dynasty (206 B.C.-A.D. 220). Emperor Han Wudi was the first to construct these islands in the lakes of his park.

The Kotoji-toro lantern at Arisugawa Park has one foot on shore and one in the pond.

Arisugawa boasts a beautiful stone lantern, similar to a famous one in Kenrokuen in Ishikawa Prefecture. Known as Kotoji-toro, the lantern is supported by two carved stone legs. One of the legs is longer than the other and rests on a stone just above the surface of the water; the shorter leg is embedded on the landward side. One section of the pond follows the deep valley to where it ends at a waterfall.

There is another waterfall to the right of the main entrance, located halfway up the side of the tree- and rock-covered hill. The construction technique used for this waterfall is impressive. Near it is a small plum garden (baien).

During the winter months two species of dabbling or marsh ducks can be seen in the pond: mallards (magamo) and spot-billed ducks. The spot-billed duck is a resident of ponds throughout Tokyo. It has a yellow patch right at the tip of its beak, while the mallard’s bill is all yellow. Male mallards have bright green heads, but the plumage of the female mallard is camouflage brown. These ducks were numerous around the pond when I went along in December. Some fishermen could be seen relaxing with a pole in their hands. The park is also home to the ubiquitous jungle crow (hashibuto-garasu).

The great ginkgo tree in Arisugawa Park

At the top of the garden, just outside the public library, there is a very old maidenhair tree (icho, Ginkgo biloba) that dates back to the days of the Nanbu lords. The exact age of the tree is unknown but, from its height and girth, it is estimated to be around 350 years old and still very healthy. The trunk is over 2 meters in diameter.

Ginkgo trees are of Chinese origin but have long being cultivated in Japan. Large trees often seen around temples and shrines. It is much planted as a street tree in Tokyo as it is well able to withstand pollution and salt.

Ginkgo biloba is the only remaining species in the ancient Ginkgoaceae family. Male and female flowers are on separate trees. Ginnan (ginko nuts) are harvested from the female trees in late autumn. They are delicious, and a usual ingredient in hot egg custard (chawan-mushi).

There are almost 2,000 tall trees growing in this park. Tall coniferous evergreens such as the Japanese black pine (kuromatsu, Pinus thunbergii), Japanese cedar (hinoki, Chamaecyparis obtusa) and the sawara cypress (Chamaecyparis pisifera) form part of the woodland canopy.

The deciduous white mulberry tree (kuwa, Morus alba) is native to Japan as well as China and the Korean peninsula. Male and female flowers are normally borne on separate trees, but occasionally on the same tree. Female flowers open in May, are white and have no petals. In July this tree bears blackberry-like fruit each 5-14 mm long. Make sure you don’t eat them before they’re completely black, or you’ll get a stomachache!

Kaya (Torreya nucifera) is a woodland understory conifer. Its oblong, edible seeds are 2-4 cm long; oil pressed from them is used for cooking. Kaya timber is light yellow, fragrant, very hard and takes a high polish. It is widely used for making bathroom basins (furo-oke) and go game boards. Kaya leaves are long and sharply pointed, which helps to differentiate it from another similar conifer, the plum yew (inu-gaya, Cephalotaxus harringtonia).

One commonly seen deciduous tree in the parks of Tokyo is iigiri (Idesia polycarpa). A fast-growing tree, its trunk is always straight and gray. Iigiri flowers are dioecious and open in May, the male flowers in panicles 20-30 cm long. Because there are no petals, the flowers are not very noticeable, but in autumn iigiri trees are laden with berries, which normally last until springtime. Wood from iigiri is used to make geta.

Muku-no-ki (Aphanathe aspera) belongs to the elm family. This tall, fast-growing deciduous tree is common throughout the Kanto and western Japan. In parks where the management has decided to set aside some areas to naturalize, this species is one of the first colonizers. Its timber is used for musical instruments and tools, and to a small extent for building.

The enoki or Japanese hackberry is very closely related and often mistaken for the muku-no-ki, but the muku-no-ki has blue-black berries and the hackberry has red berries.

Another natural colonizer is the hemp palm (shuro, Trachycarpus fortunei). Twine obtained from this tree (shuro-nawa) is widely used in Japan, especially in gardening. The twine is tough and very durable, and unlike nylon twine will not damage the bark of trees. Shuro-nawa used in Japan now is imported from China or Korea, though, because of cheaper production costs.