There’s a secret at the Cumming library. While it’s somewhat hidden, the public is invited to visit the library’s garden, located behind the building.“It is secret,” said Debbie Rainey, one of four Forsyth County Master Gardeners who maintains the spot, which appropriately enough is called the Secret Garden.It’s one of three public gardens housed at a Forsyth County library branch. The others are the Bookworm Garden at Sharon Forks in south Forsyth, and the Garden Plot at Hampton Park on the county’s north end.