Three years. Oriental ginseng, commonly known as "white muscle ginseng", also known as burdock. The growth cycle of Japanese ginseng is 3 ~ 5 years, and the content of Japanese ginseng reaches its peak in the fifth year. At this time, if it is not harvested, the content of Japanese ginseng will decrease, but its nutritional value will decrease. Considering the planting cost, most Japanese farmers' associations harvest in three to four years, which is the most cost-effective. Japanese ginseng planted for 5 years has high nutritional value.