“….a high fly into the new bleacher territory which is to be known as Greenberg’s Public Gardens.” Paul Gallico, “The Helping Hand,” New York Daily News, October 3, 1935, p66
“Zone between the new bullpen screen and the scoreboard in Pittsburgh already christened ‘Greenberg Gardens.'” Jimmy Powers, “The Powerhouse,” New York Daily News, February 28, 1947, p57
Previous earliest use (Dickson Baseball Dictionary, 3rd edition, 2009):
1947. “The ‘Greenberg Gardens’ plot in the Forbes Field … has sprouted a flourishing crop of home runs—nine in four games.” (San Francisco Examiner, Apr. 21; Peter Tamony).
NOTE: The Dictionary does not include any reference to the earlier name used in Detroit.