Cell and tissue cultures of six plant species grown with and without a mineral oil (m.o.) overlay on MS medium supplemented with appropriate growth regulators showed that the rate of growth and morphogenesis in cultures covered with m.o. was greatly reduced as compared to the controls. This lengthened the subculture period from 35–45 days to 150–240 days and resulted in significant savings in effort, material and time. Subsequently, the shelf life of encapsulated propagules of Selinum candolii, Nicotiana tabacum and Valeriana wallichii was enhanced from 25–30 days to 150–240 days. Plants were regenerated from the cultures overlaid with m.o. in each case. The results presented here explore the potential of the m.o. overlay technique and may have major implications in both the basic and applied aspects of plant tissue culture.