A supportive device and mounting system for positioning potting or planting systems on a support surface and enabling convenient and secure location, adaptive replacement and optional irrigation use. A base support member is secured to a structural support system. An insert member is adaptive positioned within the based support member enabling a smooth transition to the structural support system. Alternative irrigation systems operably interconnect each base support, member for improved convenience. A method for installing, modifying and operating the supportive device and mounting system is also provided.