Thin cell layers or TCLs have been a fundamental corner-stone of tissue culture of all plant species, including floricultural and ornamental plants (FOPs). In this review, the current status of the use of TCL technology to specific FOPs will be outlined while certain successes and difficulties will be focused. The ability to control developmental and morphogenetic processes in vitro through the use of TCLs, especially where conventional methods have not always produced ideal results, is the key in taking lab-based theory to business-based applications. TCL technology, which focuses more on the size rather than the origin of the explant, is a gateway for FOP regeneration and transformation studies. Some general principles and guidelines for quality verification will be provided.