In the United States, zones 3 to 8 are ideal regions for growing ginseng.  70% to 80% shade from deciduous trees during mid day is necessary to growing ginseng.  If there is not enough shade, the ginseng plants will burn and die.  Too much shade and the ginseng plants will grow very slowly.  The soil should be moist enough with good drainage.  Not enough drainage and you risk rotting of your ginseng roots.  Choose your growing site with caution because it could make the difference between seeing your profits in 10 to 12 years instead of 25 to 30 years. Soil composition is also important. 

Be sure to take a soil test from various locations of your site.  Keep a close eye on the soil pH and available calcium and available phosphorus.  Soil tests should be performed every year to monitor soil nutrients.