Plum Springs is a 6th-class city in Warren County, Kentucky, in the United States. The population was 447 at the time of the year 2000 U.S. Census. It is included in the Bowling Green metropolitan area. There are 2 blue holes near the entrance of Grogan Street, which converge to form a stream which empties into the Barren River. When the water is low a cave is accessible at one blue hole. It is named for its location on Plum Springs Road (Ky.