At the heart of Ashikaga Flower Park stands a single wisteria vine, a hundred and sixty years old, its branches trained across a trellis the size of six hundred tatami mats. When it blooms, in mid-spring, the purple flowers hang down from overhead in long trailing cascades, so that you walk beneath a ceiling of falling color. It is one tree. It looks like weather.

The festival lasts about a month, from mid-April into mid-May, and it is timed to the flowers' own sequence. The wisteria opens in order — pale pink first, then violet, then white, then yellow — so that the garden changes color week by week. More than three hundred and fifty wisteria plants bloom across the grounds, threaded through with five thousand azaleas.

After dark the great vine is lit, and the illuminated wisteria has been compared to the glowing tree of souls from the film Avatar — the light pooling beneath the trellis like water, the flowers suspended in it. The park has been recognized as one of Japan's night-view heritage sites for this alone.

There is a particular pleasure in a flower you stand under rather than over, that surrounds you rather than lines your path. For a few weeks between spring and early summer, the garden becomes a canopy — a whole season spent, briefly, beneath the color of wisteria.