SUMMARYWe have examined the effects of environmental conditions on the sprouting of micropropagated bulblets ofLilium speciosumwith various levels of dormancy. After planting at low temperature (15°C) orin vitro, a higher percentage of bulblets sprouted than after planting at high temperature (20 or 25°C) or in soil. Dormancy was relative, i.e. bulblets with deep dormancy were capable of sprouting at a limited range of conditions and bulblets with low or no dormancy at a wide range. The promotive effect of thein vitrocultivation was, to a large extent, caused by exposure of the bulblets to light which was absent after planting in soil because of coverage by a layer of soi