Yellow Cress (Rorippa sylvestris(L.) Besser), a weed difficult to control when established, has recently invaded Swedish nurseries. The properties of the species, as well as measures to avoid its further spreading, are described based on an exhaustive dissertation, other literature and own observations. It is most important to apply preventive measures to stop the species from being introduced and to observe the first establishment phases of the species. If it becomes established it is exceedingly important to prevent the spread of vegetative reproductive organs to unaffected areas.