Every year, the Japan Federation of Landscape Contractors hosts an amazing event called the Kei Truck Garden contest. Large decorative gardens are recreated in miniature on the backs of pickup trucks, then put on display and judged. The gardens are planted by landscape artists in the iconic Japanese Kei trucks, little pickup trucks whose diminutive size is meant to make them easily to maneuver through the narrow streets common in Japan. They are particularly favored by Japanese landscapers, so they were a natural choice to serve as a base for the mobile landscaping competition.
You can see more of the lovely truck garden entries on the website of the Osaka branch of the Japan Federation of Landscape Contractors.