Valerian Hardiness

Can you tell me what zone valerian is hardy in?

Most authors say that valerian is hardy in zones five to nine. However one author says the plant is hardy in zones two to nine. We are located in zone five but several zones come very close to us because of the influence of Lake Ontario and we frequently get zone four and if we are lucky like the winter of 1997-98, zone six winter temperatures. Valerian has never been winterkilled on our farm. If you are in a colder zone, you will have to find a sheltered spot and the plant will probably do fine. Not all plants are so forgiving though!