The in vitro micropropagation of oca (Oxalis tuberosaMol., Oxalidaceae) on a medium with 30 g/litre versus 60 g/litre sucrose had no effect on multiplication rates and general plant phenotype. The only differences noted at the higher sucrose concentration were shortened internodes and more robust stem tissue, which provided a plant growth form more appropriate for micropropagation and transplantation out of culture. Substantially increased starch concentrations were measured in leaves, stems, and roots of the oca plants cultured on the high‐sucrose medium. Oca plants cultured in vitro on a medium with 60 g/litre sucrose showed markedly improved growth in soil following transfer out of culture. This was attributed to the in vitro plants accumulating and storing more reserves when grown on the high‐sucrose medium.