Abstract: This study provides detailed reproducible methods for the transformation of Dendranthema X grandiflora Shuhou-no-chikara (standard) and Lineker (spray) stem internode Thin Cell Layers (TCLs) and conventional stem internode explants, using intron-containing and intron-less plasmids. Discussed methodologies and results have used GUS reporter, nptII selector genes, as well as pac1/2,5-A/RNaseL genes coding for virus/viroid resistance. Transformation efficiencies are reported at the kanamycin selection (callus formation and plantlet rooting), GUS, PCR, Southern and Western levels. Notes on regeneration improvement through the use of TCLs, as well as the effective use of sonication for both regeneration and generation of transformants, stimulation of Agroinfection and elimination of Agrobacterium, are included. Protocols are provided for the use of scanning electron microscopy to confirm developmental processes, as well as flow cytometry to check for cell competence and division stages. The difficulties still experienced in the genetic transformation of chrysanthemum globally by researchers require a detailed protocol that exposes the subtleties in methodology. This study provides that information source.