Cold stratification requirements for germination of Alliaria petiolata

Garlic mustard is among the most important invasive weeds of North American eastern deciduous forests. Investigations of the mechanisms that enable its success as an invader require a simple method to propagate this weed in the laboratory and the greenhouse; we develop such a method in this study. Cold treatment (24-h dark cycle; maximum 6 C, minimum - 1 C) for at least 100 d on a moist organic mix, followed by incubation at temperatures approximating spring (maximum 15 C, minimum 6 C), results in close to 100% germination. The information presented here will be valuable in studies requiring a steady supply of garlic mustard plants for experimentation and for the mass rearing of biological control agents.