Embryo dormancy in seeds of Impatiens glandulifera Royle can be overcome by maintaining them imbibed at 4 °C. The period of chilling required depends on the age and storage conditions of the dry seed; it decreases with seed age and is reduced by a high storage temperature. Fully imbibed seeds can remain dormant for several years at 20 °C if the stratification requirement is not met. Interrupting stratification at 4 °C with a period at 20 °C increases the chilling requirement in proportion to the length of the warm period. However interrupting stratification by desiccation has no effect on the chilling period required. The ecological implications of these findings are discussed.