They grow valerian as an annual root crop. They get the transplants into the field first thing in the Spring and then harvest the root in the late Fall. Valerian prefers a lot of moisture throughout the growing season.
The root is used medicinally and there are opposing viewpoints regarding the herb’s effects on the body. Many people find the herb warming and calming to the mind and body, even sleep-inducing, while others believe it’s actually a cerebral stimulant. Regardless, in both Europe and North America, the herb is marketed as a sleep aid.