Home / Perennials / Creeping Phlox ‘Fort Hill’ Creeping Phlox ‘Fort Hill’ Creeping Phlox ‘Fort Hill’ shows off beautiful lavender/purple flowers for several weeks beginning in April. lThis low growing perennial tops out at 4-6 inches high and can spread 1-2 feet wide.Blooms best in full sun. Hardy in zones 3-9.