The transplanting to soil of bulblets of Lilium longiflorum Thunb., L. × formolongi, L. speciosum Thunb., and L. auratum Lindl., grown on Murashige and Skoog’s medium, was investigated in relation to dormancy. Leaf emergence from tissue-cultured bulblets was inhibited after transplanting into soil without low-temperature treatment. To break dormancy, low temperature (5°C) treatment for 70 days was required when bulblets were produced in the medium with 30 g/liter sucrose, while 120 to 140 days were required when bulblets were produced in the medium with 90 g/liter sucrose. In vitro-produced bulblets of L. longiflorum grew well in soil and about 40% of the bulblets flowered in a year.