How did Hokusai’s Great Wave bloom across Brussels’ Grand-Place?

Brussels transformed the Grand-Place from 13 to 16 August into a Belgian-Japanese artwork, covering nearly 1,300 square metres with more than 500,000 dahlias arranged as a contemporary version of Katsushika Hokusai’s Great Wave off Kanagawa. The completed Tapis de Fleurs, designed by Japanese artist Hiro Sugiyama and his Enlightenment collective, remained on view for four days before the flowers were removed after Sunday’s programme.

For people in Brussels, the installation was both a major city-centre event and a highly visible act of cultural diplomacy. The Grand-Place remained freely accessible, while paid visits to the City Hall balcony and tower offered elevated views. The City of Brussels also staged sound-and-light shows, and a second floral carpet inspired by hops appeared at the Bourse, creating a route between Japanese imagery and Belgium’s brewing heritage.

The City says volunteers normally transfer the full-scale design onto a transparent, perforated sheet and place the flowers in a matter of hours. This year’s result translated the foam, curves and looming wave of Hokusai’s early-19th-century print into densely packed dahlias. Sugiyama called his design Neo-Hokusai, combining the visual language of ukiyo-e printmaking with contemporary graphic art.

The international connection was deliberate rather than decorative. Belgium and Japan are marking 160 years since their 1866 Treaty of Friendship, Commerce and Navigation. Belgium’s Foreign Affairs ministry included the carpet among the anniversary programme’s principal cultural events, following Emperor Naruhito and Empress Masako’s June state visit, during which King Philippe and Queen Mathilde received them in Brussels and Leuven.

Federal officials present the relationship in strategic as well as ceremonial terms. The Foreign Affairs ministry says more than 280 Japanese companies operate in Belgium and support nearly 30,000 jobs in industries including logistics, chemicals, biotechnology and automotive manufacturing. At the anniversary’s opening ceremony, Deputy Prime Minister Jan Jambon described Japan as Belgium’s second-largest non-European foreign investor. The EU institutions were not organisers of the carpet, however, and no separate EU policy initiative was attached to the display.

Two readings of the event sit alongside each other. Nawal Ben Hamou, Brussels alderwoman for culture and president of the organising non-profit, framed the Tapis de Fleurs as an emblem of the city’s international appeal. Economy alderman Didier Wauters emphasised the opportunity for shops, restaurants and craftspeople expecting large visitor flows. Sugiyama’s perspective was more artistic: his wave evokes nature’s force and the possibility of reworking a Japanese image through a distinctly Brussels medium. Neither interpretation cancels the other, but they reveal the familiar tension between ephemeral public art and destination marketing.

That tension matters on the Grand-Place. UNESCO, which placed the square on its World Heritage List in 1998, describes it as an exceptional mixture of architectural and artistic styles while warning that the surrounding historic district faces strong commercial and tourism pressures. The carpet temporarily changes the experience of the protected square without permanently altering its fabric, one reason the short-lived format has endured.

The tradition began on the Grand-Place in 1971 and is now generally organised every two years around the 15 August weekend. Japan previously partnered with the event in 2016, making the 2026 edition a return as guest of honour rather than a first encounter.

The full-sized Neo-Hokusai has now disappeared, as intended. Its miniature counterpart at Mini-Europe is due to remain until the 2028 edition, preserving the design after the dahlias have gone. Organisers have not yet announced the next full-scale theme, leaving the future artistic partner—and how Brussels will balance spectacle, diplomacy and heritage—to the next cycle.