Cyclamen is grown under a germ-free condition, the end portions of some or all of its roots are cut off, and the cyclamen is cultured in a suitable medium to grow root tubers (bulbs) at these portions. The root tubers are cut off and cultured to be germinated and rooted in order to produce the genetically same individuals (clonal plants). Thereby, cyclamen root tubers are produced stably and efficiently, thereby providing clonal plants.