In spring it is delightful to see, as the poet William Wordsworth described it, "the budding twigs put out their fan to catch the breezy air."

Next Tuesday is Midori no Hi (Greenery Day), and if your fancy is for a gentle, vernal brush with nature, you might enjoy a visit to the Sankeien Garden in Yokohama's Honmoku district.

This is an exceptional Japanese garden, which is now at its freshest, with fragrant spring azaleas, trickling streams embroidered by ferns and vistas of the three valleys from which it takes its name. In addition, historic buildings such as tea-ceremony houses, summer pavilions and a three-story, 15th-century pagoda blend into the landscape, giving the garden unique interest and charm.

Surprisingly, this green treasure backs onto a coastline of oil refineries and reclaimed land -- although of course it wasn't always so. When the cultivated silk merchant Tomitoro Hara opened the garden to the public in 1906, Honmoku was a picturesque headland of small beaches and fishing boats. A painting from the early Taisho Era (1912-1926) in the garden's Sankei Memorial Gallery shows the view Hara would have had from his mansion, looking over a reedy pond to the hilltop pagoda and the sea beyond.

Unfortunately, a look in the same direction today will reveal an industrial chimney rearing up behind the garden, painted pale blue in an effort at camouflage. However, the pond is still there, and the day I visited, a white egret was wading among the stalks of last summer's lotus blossoms.

A few years ago, an expatriate journalist, Kunio Francis Tanabe, recalled his childhood in Honmoku around the time of World War II. He wrote: "We would go through the woods that led to Sankeien, to a clearing where the three-story pagoda stood high above ocher cliffs and wind-blown pines. Near the pagoda we found wild akebi fruit, which we proudly took home. My brother and I used to go hunting with air gun and slingshot in search of Korean pheasants and quail. We saw them, but never hit one."

I don't know about pheasants, but akebi (Akebia quinata) vines are still twining through the woodland, and in this season they are flowering, too. If you look carefully you might find their three-petaled, purple-brown flowers, hanging down like tiny chocolate bells. I was also delighted to find the strange, striped, flower sheath of the urashima-so raising its head by a woodland path. This plant is a striking member of the arum family, which includes the American "jack in the pulpit" and the English "cuckoo pint." It has a spathe, or thin sheath, that folds round a spadix bearing minute flowers. This particular species (Arisaema thunbergii ssp. urashima) has a surprisingly long, thin spadix it flings out like a fishing line. The plant is called "Urashima's weed" in Japanese, because of an old folk tale about a fisherman called Urashima Taro.

In Sankeien's spacious "outer garden," the planting is naturalistic and done with the lightest touch. Sprays of clear yellow yamabuki (kerria flowers; Kerria japonica) are allowed to trail over banks or study their reflections in the pond. Clusters of fragrant shaga (fringed iris; Iris japonica) are growing happily on the banks of a stream or beneath plum trees. As the plum trees are now just coming into leaf, early flowering plants such as these irises, violets and even the shirobana-tanpopo (white dandelion; Taraxacum albidum) were thriving in the dappled shade.

Describing a green glade in spring, Wordsworth wrote,

Through primrose tufts in that green bower
The periwinkle trailed its wreathes,
And tis my faith that every flower
Enjoys the air it breathes.

Of course, he was right, and our garden plants are happiest if we give them a setting that suits their nature. In Sankeien, many plants have been left to find the ideal spot for themselves, while others have been given a helping hand by the gardeners. The violets here, for example, look equally attractive springing up around mossy tree roots or placed in a low stone wall. But violets will flower happily in a pot on the balcony, too. If you have bought a potted violet this spring, don't discard it when it finishes flowering, but try planting it in a container with some dainty herbs such as wild strawberry and ornamental sage. It can hide from the strong summer sun among the other plants, and although it will disappear below ground for winter it should flower again next year.

After exploring the outer garden, you'll find the inner garden has a more intimate atmosphere. The main focal point is a beautiful old villa, dating from 1649, which Hara had the foresight to bring to Sankeien and preserve. Now, it is the only residence of its kind that remains, and with its open architecture it is a timely reminder that the Japanese used to live in touch with the natural world.

Around the villa, the clipped lawns and more formal arrangement of trees, stones and paths create a profound sense of tranquility. As I paused by the veranda, an old man slowly crossed a wooden bridge. He disappeared into a valley blurred with young leaves and spring mist, and the scene seemed like an ancient Chinese ink painting, where a tiny human figure merges into the vastness of nature.

This valley is a memorable example of the Japanese ability to "borrow" a natural landscape and incorporate it into a manmade garden. If we think about it, the valley is actually not so vast or deep, but as we cross the bridge, we look down on a winding stream and up to a path that curves out of sight, with a glimpse of a tea hut in the distance. And this light, subtle landscaping leads us on to a journey to the heart of spring.