Every summer the city of Brussels assembles an enormous carpet of begonias, under the advisement of one hundred experienced gardeners. The project is planned far in advance, with illustrations and scale models based on a chosen theme (previously chosen have been the arms and shield of a town or commemoration of important events). This year's theme features Saint Michael striking down the dragon, the official protective image of the city, founded over 1,000 years ago.
What's amazing is the incredible carpet is assembled in just 4 short hours. More on the process, via Brussels' Flower Carpet website:
"The day before, the spaces between the floral patterns will already have been filled with rolled turf. The flowers are packed together one by one, 300 to every square meter of the ground, (+/- 750.000 flowers!) so tightly (no soil is used at all) that they won't be blown away by the first puff of wind, and create their own microclimate. In heat waves, the turf has to be watered to prevent it from shrinking, but if the weather is too wet, the grass can grow 4 to 5 centimeters in 3 days!"