Then, there's the heavy perfume of the flowers and the scent of crushed grass being trampled by a thousand feet. And the colours: beautiful turquoise kimonos, rich pink trees and even the amazing sushi that seems to be part of everyone's picnic.

To be honest, there's also a great deal of mess that includes everything from discarded paper cups to Asahi beer cans. And a lot of noise: singing, music from ghetto-blasters, loud conversation and lyrical laments.

Most amazing of all is seeing a whole lot of Japanese people letting their hair down — just about the only time in the year you'll come across such relaxed merrymaking.

Blossom viewing parties

It's the climax of spring, the most celebrated time on the Japanese calendar, when the entire nation explodes with cherry blossom fever. On television, the arrival of the blossoms is forecast breathlessly every day as the wave of flowers creeps up from the south and hits central Japan like a pink-and-white blizzard.

"Hanami", or parties for the viewing of cherry blossoms, start at the appearance of the earliest buds and continue until the last few petals drop off the trees.

Portable karaoke machines get pressed into service; drunken singers belt out 'Sakura, Sakura', a lament to the short life of the cherry blossoms. Children run about flinging fistfuls of fallen flowers over everyone like wedding confetti. And everywhere, blue tarpaulins are laid out under the cherry branches to be quickly covered with family picnics.

Visitors can easily join the picnicking by stocking up in the open-air markets found in most cities, where you can buy "bento", plastic boxes divided into segments containing rice, pickles, sushi and other treats.

A short season

If you want a change from sometimes riotous hanami parties, temples and castles across the land host tea ceremonies, traditional music recitals and costumed processions in honour of the cherry flowers.

The Japanese are also always happy to discuss the finer points of cherry varieties, from the stunning "yamazakura" or mountain cherry, with its very pale pink petals, to the startling weeping cherry with its long, trailing branches.

The blossoms' moment of glory is surprisingly short. The cherries bloom for not much longer than a week and are seen in their full glory for only a couple of days. No wonder the hanami is both a time of intense celebration and slight melancholia, for the Japanese have realised the transience in the best moments of life.

Within a week, the cherry blossoms have faded. Nature packs up her paintbox and the pink explosion retreats like a mirage, leaving only unforgettable impressions.

Blossom fever: when

Depending on the weather, the cherry blossoms make their appearance any time from early to late April in central Japan. The first blooms appear in Okinawa, in Japan's southern islands, in March and the last flowers don't fade in Hokkaido in the far north until well into May. If you're travelling in Japan in April, though, you're sure to come across some blossoms somewhere.

Blossom fever: where

• Kyoto

  Probably has the best flower displays in Japan. Walk the famous cherry-lined Philosopher's, then head to Murayama Park, a local favourite where some of the trees are illuminated at night. At Heian Shrine you can see beautiful weeping cherries and seasonal tea ceremonies. The Cherry Blossom Festival, held at Daigo-ji Temple, features a procession of locals in gorgeous traditional costumes.

• Osaka

  Has a fine display of 4000 trees in the parks of Osaka Castle. For your hanami, head to Kema-sakuranomiya Park, where four kilometres of riverbank are lined by cherries. The grounds of the Mint Bureau here are also open to the public, and feature more than 100 varieties of cherry trees. Other fine blossoming parks are Expo '90 Commemorative Park and Sumiyoshi Park.

• Yokohama

  Features 2000 cherry trees in Sankei-en, a purely Japanese-style landscaped garden, some of which have evening illuminations. Performances of the "koto" (Japanese harp) feature in the evenings in early April.

• Odawara

  Hosts a Cherry Blossom Festival in its castle in early April, featuring an open-air tea ceremony and a parade of children in festival attire. There's also night viewing of the blossoms by lantern light.

• Tokyo

  Can look beautiful during the cherry season. Ueno-koen Park is the most famous and popular site for hanami. Other favoured spots include Koishikawa Koraku-en Garden near Tokyo Dome and Chidorigafuchi Park, where the trees are particularly impressive illuminated at night. Shinjuku Gyo-en Garden is where the Prime Minister of Japan hosts his grand hanami party. There are thousands of trees, but thousands of people too.