Daio Wasabi Farm

Wasabi is difficult: it needs cold running water, constant temperature, shade and clean gravel, which is why almost nothing grows it well and why most of what is sold as wasabi anywhere is horseradish and mustard dyed green. The Azumino basin is fed by snowmelt from the Northern Alps that emerges as spring water at a steady thirteen degrees or so, and this farm - about fifteen hectares, the largest in Japan - grows the plants in long gravel beds through which that water is continuously flushed, shaded in summer with black netting. It takes a year and a half to grow a rhizome to size. Three wooden waterwheels stand on the stream beside the farm; they were built as a set for Akira Kurosawa's Dreams in 1990 and were kept. Everything on sale is wasabi-flavoured, including ice cream and beer, and fresh rhizome is sold with a shark-skin grater.

What you actually see

• Gravel beds flushed with spring water - fifteen hectares, the largest wasabi farm in Japan.
• Thirteen-degree water - Alpine snowmelt emerging at a constant temperature.
• Summer shade netting - black cloth over the beds through the warm months.
• Kurosawa's waterwheels - built for the film Dreams in 1990 and left in place.

When to go

April to October; the beds are uncovered and greenest in spring. Two hours.

Honest expectations

It is free and consequently very busy with coach parties. Everything is wasabi-flavoured to a degree that becomes tiring. Fresh rhizome loses its heat within minutes of grating and does not travel well. Summer netting hides the beds.

Nearby

Matsumoto and its castle are south; the Alps rise to the west.