In 1946, Dick Fagan returned from World War II to resume his journalistic career with the Oregon Journal. His office, on the second floor above Front Street, gave him a view of not only the busy street, but also an unused hole in the median where a light pole was to be placed. When no pole arrived to fill in this hole, weeds took over the space. Fagan decided to take matters into his own hands and to plant flowers.

From http://www.portlandonline.com/parks/finder/index.cfm?action=ViewPark&PropertyID=265 (pictures there, too!)